Text-Only Origami Instructions - Copyright 2025 by Lindy van der Merwe and Nishi Sakpal
accessorigami.com
This tutorial is divided into the following sections:
1. Introduction
2. Terms Used
3. Tips for Constructing the Icosahedron
4. Construction
4.1 Row 1
4.2. Row 2
4.3. Row 3
4.4. Row 4
5. Closing the Icosahedron
6. Summary of 30-unit Construction
1. Introduction
The icosahedron is one of the five Platonic solids, the others being the tetrahedron, the cube, the octahedron, and the dodecahedron.
You can read more about these fascinating geometric shapes at
Cuemath
There are many ways to construct these and other geometric shapes, with and without using glue or tape. In this tutorial, 30 Sonobe units
are used to construct an icosahedron.
For text-based information on how to fold the Sonobe Unit, visit
accessorigami.com
It’s suggested to at least complete structures of 3 and 6 units before moving on to 30 unit assemblies, as experience is valuable for more challenging modular assemblies. You will likely need a lot of time, patience, and some tenacity. It’s normal to grapple with constructions and return to them later. Understanding the concepts in this type of construction and developing fine muscle movement and memory will allow you to eventually construct geometric structures with ease. If you have folded the Sonobe octahedron, many of the concepts used in this tutorial will be familiar to you.
Apart from their beauty and the challenge of construction using origami, hollow, round geometric shapes are also great to use as decorations and as closed containers to present as gifts with something inside (if you don't mind your construction being disassembled by the recipient, that is).
Before continuing, take time to fold at least around 40 to 50 Sonobe units that all look the same.
Important: For each unit, add a diagonal crease from top left to bottom right. Fold it back and forth once or twice without overdoing it to maintain springiness.
If you would like to start with construction immediately, you can now skip to Section 4.
2. Terms Used
2.1. Icosahedron
One of the five Platonic solids with 20 equilateral triangular faces, 30 edges, and 12 vertices. Picture the icosahedron as a round object with fairly blunt points sticking out from its surface. You will shape the model from the bottom, working in a circle from a center point, widening, and ending at another center point at the top.
2.2. Units
In this tutorial, 30 Sonobe units are used to create the icosahedron.
2.3. Flap
Each unit has two points or flaps to be inserted into pockets of other units.
2.4. Pocket
The central area of each Sonobe unit has two pockets where the flaps of other units will be inserted.
2.5. Face
The outside of a geometric structure. E.g. for a cube, you'll see 6 flat square faces, while for the icosahedron, 20 bent triangular faces. While construction is taking place, the faces will appear as diamond or triangular shapes with slanting sides or edges with flaps and pockets.
2.6. Edge
While assembling, will have edges. This is what we will feel if we trace the outline of a unit or a structure.
2.7. Pyramid
The model is made by constructing "pyramids"—triangular shapes that stand out from the model’s surface.
Keep in mind that for this model, each pyramid is formed where 3 units slot together.
There will be 20 pyramids and 30 units.
So, don't be confused by the figures in the instructions below. It will make sense as you proceed with the assembly.
2.8. Orientation
- Working orientation
How you hold your model while inserting flaps, sometimes involving holding it in the air or placing it down temporarily. The "inside" of the structure faces you.
Flat orientation
Primarily used in the beginning stages of construction, the assembly is turned with its inside facing the table, opened and pressed flat. In this orientation, it’s easier to count pyramid structures as they stand up from the model’s flat surface. Ensure all pointy flaps are tucked in underneath the model when in the flat orientation.
3. Tips for Constructing the Icosahedron
3.1. Paper Choice
Use paper around 6 x 6 inches with a rough texture. The paper should be rigid enough to hold its shape. Consider using very thin cardstock, thick construction paper or even braille paper.
3.2. Prepare Units
Fold enough units before starting assembly. It's suggested to fold double the amount needed. This helps with orientation, especially for beginners.
3.3. Accurate Folding
Fold as accurately as possible. Any slight misalignment in points and edges can cause problems during assembly.
3.4. Glue and Tape
Once practiced, no adhesive is needed. However, beginners may find glue or some kind of tape helpful while learning to construct the model. Be cautious, as glue or tape can make adjustments dificult and messy.
3.5. Unit Quality
If units are torn, tacky, or flat, start over with new ones. Compromised units can cause the model to lose shape and fall apart.
3.6. Springy Units
Ensure units feel springy. They should resemble an origami bird with wings open at a 45-degree angle.
3.7. Uniform Folding
Ensure all units are folded similarly, with pockets on the central square faces.
If you omit tucking in the corners to lock the units before turning them over, you will find only a flat surface, with no pockets to use.
3.8. Marking the Center
Mark the bottom center point of the shape. Beginners may find it helpful to secure this point with glue tack for better orientation during assembly.
3.9. Work Area
Use a large tray with a small rim or a flat lid of a box. Keep units on one side and work on the model on the other.
3.10. Organize Units
Keep units in a container and take them out in groups.
3.11. Keep Count
Keep track of the units you insert and those remaining to better understand the row construction.
3.12 Follow Instructions
Do not insert any points other than those specified in the instructions, even if frustrated.
3.13. Diagonal Fold
Ensure all Sonobe units have a diagonal fold across the square. This is necessary for the tetrahedron, octahedron, and icosahedron.
4 CONSTRUCTION
4.1. Row 1
Row 1 will have 5 pyramids radiating from a center point and will need 10 units. Think of it as a bowl-like formation with a small central hole surrounded by 5 pointy pyramids. The construction starts from the left and moves to the right in a circular shape.
Pyramid 1 (First Half Cube) - Units 1, 2 and 3
Summary: Start with unit 1, add unit 2, add unit 3, join unit 1 at the back of unit 3.
A. - Hold your first Sonobe unit with pockets facing away, flaps at the top and bottom. Let the bottom flap rest on the table.
B. - Hold unit 2 with flaps left and right, insert it into the right pocket at the back of unit 1. Hold them together.
C. - Take unit 3, hold with flaps top and bottom, coming from above, insert the flap of unit 3 into the back of unit 2.
D. - Bend unit 1 slightly right, insert it into the pocket at the back of unit 3. You should have a half cube with 3 connected square panels and 3 loose flaps.
E. - Fold in all flaps to lay flat against the inside sides of the half-cube.
F. - Reinforce Pyramid 1 by turning the assembly with the open side on the table (flat orientation). You should feel a point standing up at the center. Press down to accentuate diagonal lines while flattening outer edges on the table.
Note 1
A. Identifying faces Make sure you can identify the 3 faces of your pyramid in this orientation. One will be nearest you, another will be on the right and the last will be on the left. The faces will still be square, but they will now be in a diamond-like orientation with one part of each face standing up, forming the actual pyramid and the other part of each face will form a triangular point that is flat on the table.
B. Identifying edges with pockets and flaps Trace the pyramid outline. It is six-sided. The face nearest you will have an open edge with a pocket on the right and a pointy flap on the left. This pattern is the same for the remaining faces.
G. - Pick the pyramid up and turn it so it is in the working orientation again.
Pyramid 2 - Units 4 and 5
Summary: Add unit 4, add unit 5, join unit 5 on the right with unit 4.
A. - Hold the structure in the working orientation and choose any open edge with its pocket. Turn the figure so the chosen pocket is facing away from you and so you can access it from the right. We will call this unit 3.
B. - Hold unit 4 with its flaps on the left and right and insert it into the right pocket at the back of unit 3.
C. - Find the flap of unit 3, which should be standing up just to the left of unit 4. Hold it up, ready for the next step.
D. - Take unit 5 and, holding it with its flaps at the left and right, insert the flap of unit 3 into the back of unit 5.
E. - Now, bending unit 5 slightly to the right, insert it into the pocket at the back of unit 4. Once done, you will still have a structure that looks a bit like a lopsided cube.
F. - Keeping the points tucked against the inside of the figure, turn the assembly with its open side to the table. Carefully spread the model so that you can feel the pyramid shapes standing up. You should now feel 2 points standing up at the center of the structure. There should be one nearest you and another furthest away, with a straight line separating them, like a valley.
G. - Pinch the new point between your fingers while pressing down on the structure, so that you can accentuate the diagonal lines of the model. Press down as much as the structure will allow. You want the outer edges of the figure to lie flat on the table. Look at the outline of your assembly. If you trace your finger around the shape, you will now find 8 outer edges, or 4 faces, each with a pocket and a flap.
H. - Note the face nearest you, on the right of the structure. You are specifically looking for the open edge with its pocket, since this is where you will be inserting your next unit. Once you find the diagonal opening of the pocket, keep hold of it when you turn the model over.
I. - Like you did before, turn the assembly back into the working orientation and place the figure so you are able to access the pocket you are holding, coming from the right.
Pyramid 3 - Units 6 and 7
Summary: Add unit 6, add unit 7, join unit 7 on the right with unit 6.
A. - Make sure your assembly is in the working orientation with the flap you identified in the previous step on the far right. Alternatively, just hold the structure in the working orientation and choose any open edge with its pocket. Turn the figure so your chosen edge with its pocket is facing away from you, so you are able to access this pocket coming from the right. We will call this unit 5.
B. - Hold unit 6 with its flaps on the left and right and insert it into the right pocket at the back of unit 5.
C. - Find the flap of unit 5, which should be standing up just to the left of unit 6. Hold it up, ready for the next step.
D. - Take unit 7 and, holding it with its flaps at the left and right, insert the flap of unit 5 into the back of unit 7.
E. - Now, bending unit 7 slightly to the right, insert it into the pocket at the back of unit 6. You will find that your model is becoming longer, forming a kind of semi-circle now.
F. - Keeping the points tucked against the inside of the figure, turn the assembly with its open side to the table. Carefully spread the model so that you can feel the pyramid shapes standing up. You should now feel 3 points standing up at the center of the structure. Turn the shape so that one of the pyramids is nearest you with another behind it and the third should be furthest away from you - almost as if the 3 pyramids form a little train.
G. - Pinch the new point between your fingers while pressing down on the structure, so that you can accentuate the diagonal lines of the model. Press down as much as the structure will allow. You want the outer edges of the figure to lie flat on the table. Look at the outline of your assembly. If you trace your finger around the shape, you will now find 10 outer edges, or 5 faces, each with a pocket and a flap.
H. - Note the face nearest you, on the right of the structure. You are specifically looking for the open edge with its pocket, since this is where you will be inserting your next unit. Once you find the diagonal opening of the pocket, keep hold of it when you turn the model over.
I. - Like you did before, turn the assembly back into the working orientation and place the figure so you are able to access the pocket you are holding, coming from the right.
Pyramid 4 - Units 8 and 9
Summary: Add unit 8, add unit 9, join unit 9 on the right with unit 8.
A. - Turn the figure so your chosen edge with its pocket is facing away from you, so you are able to access this pocket coming from the right. We will call this unit 7.
B. - Hold unit 8 with its flaps on the left and right and insert it into the right pocket at the back of unit 7.
C. - Find the flap of unit 7, which should be standing up just to the left of unit 8. Hold it up, ready for the next step.
D. - Take unit 9 and, holding it with its flaps at the left and right, insert the flap of unit 7 into the back of unit 9.
E. - Now, bending unit 9 slightly to the right, insert it into the pocket at the back of unit 8. You will find that your semi-circle is becoming even longer now.
F. - Keeping the points tucked against the inside of the figure, turn the assembly with its open side to the table. Carefully spread the model so that you can feel the pyramid shapes standing up. You should now feel 4 points standing up at the center of the structure. Turn the shape so that one of the pyramids is nearest you. There will now be a train of 3 pyramids behind the first.
G. - Pinch the new point between your fingers while pressing down on the structure, so that you can accentuate the diagonal lines of the model. Press down as much as the structure will allow. You want the outer edges of the figure to lie flat on the table. Look at the outline of your assembly. If you trace your finger around the shape, you will now find 12 outer edges, or 6 faces, each with a pocket and a flap.
H. - Find the place where there seems to be a triangular cut-out or gap when you trace the outer edge of the figure. Rotate the shape so that the gap is nearest you. In the next steps, we will be closing the gap you have identified, which will complete the bottom row or base of our icosahedron.
I. - Now, gently take the figure on both sides and flip it over, away from you, so that the triangular gap is now on the side furthest away. Tuck down all the flaps you can find so they are flat against the inside of the shape. Your assembly is once again in the working orientation, but now it will look more like a bowl with 4 hollow compartments or divisions.
Pyramid 5 - Unit 10
Summary: Join units 1 and 9, add unit 10 and tuck it into the unit to its right.
A. - Locate the gap between units 1 and 9 and close it by inserting the flap on the right into the unit on the left. Once the two edges are joined, the gap will be gone. Don't let go of the place where you have joined these two units. You will need the flap of the left unit that is standing up straight for the next step.
B. - Now, take the new unit 10 and hold it with its flaps at the left and right. Insert the point that you are holding from the previous step into the pocket at the back of unit 10.
C. Lastly, tuck the right flap of unit 10 into the pocket on its right. It will feel a bit strange, as if you are bending the unit when you do this. However, once tucked in, your shape will be symmetrical.
Note 2
The base of the icosahedron is now completed.
A. Flat orientation
Turn the model over, but do not press it flat like before. You will have something vaguely resembling an umbrella, with spokes radiating out from a center point. It will actually be a tiny hole, which you should try to keep as small as possible. This will be a nice reference point for you, though. There will be 5 spokes, each ending in a small triangular mountain. If you follow each mountain away from the center and downwards, you will find a square or diamond shape that ends at a point that will touch the table.
B. Working orientation
If you turn the shape back into the working orientation, the inside of the bowl-like figure will comprise a center point with 5 valley-like divisions radiating out to the edges of the figure.
From hereon, you won't have to turn the model over anymore. You will simply be adding units while the figure is in the working orientation.
C. Faces and Edges
Along the outer rim of the bowl-like structure, its edge will not be straight. You will notice a wavy pattern of edges that slope up and down, forming triangular points that will face the ceiling.
These edges are the same flaps and pockets of the faces we were able to feel in the flat orientation. They are now simply viewed from another angle.
Looking at our model so far, we will find 5 faces, each with a pocket and a flap.
Result: We have used 10 units to create a ring of five pyramids in our first row.
4.2. Row 2
Row 2 will have 5 more pyramids added in a circle around the base you have just created, each time using 2 units.
You may start at any existing face and work towards the right in a circular fashion.
--Pyramid 6 - Units 11 and 12
Summary: Choose the pocket of an existing face, add unit 11, add unit 12, join unit 12 on the right with unit 11.
A. - Choose any one of the faces and locate its pocket which will be on the right.
B. - Insert the point of a new unit into the pocket.
C. - Hold up the triangular flap just to the left of your chosen pocket.
D. - Insert this flap into another new unit.
E. Join the right flap of this last new unit into the back of the other new unit, which will be on the right.
Pyramids 7 to 10 - Units 13 to 20
This pattern should be repeated four more times as we move, always towards the right, constructing this second row of the icosahedron.
Result: We have used 10 more units to complete five more pyramids and our second row.
4.3. Row 3 -
Note 3
construction of the third row may be seen as a combination of the first and second rows.
You may start at any existing face and work towards the right. So, we will be joining two existing units and add a new unit, repeating this pattern 4 more times.
This row could also be likened to the formation of five tables or ledges, since we are now closing or pulling our structure together and towards the closing point at the top.
Your construction will be more elaborate now, but it will still seem floppy, as if it may fall apart at any moment. Things will look much better after you have added five more units in this row.
Looking at the faces of your model now, they will each have a pointy flap on the right with an open edge on the left. If you follow this open edge downwards to the left, you will find an opening resembling a slit, with a flap that seems to lay sideways. You will be joining this flap to the left, so it will close the slit or gap that has formed between the five parts making up the circular structure.
Pyramid 11 - Unit 21
Summary: Locate the slit and sideways flap, join the flap into the pocket to close the slit, lift up the flap just above the pocket you have just used and join it to the back of a new unit; join the right flap of the new unit to the right.
A. - Choose any one of the faces and locate its open edge which will be on the left.
B. - Follow the edge to the left and downwards until you find a slit with a flap just next to it that is situated sideways.
C. - Insert the point of this flap into the pocket towards the left. These two elements, namely the pocket on the left and the flap on the right, will already be adjacent to each other, so the join should feel quite natural and obvious.
- Once the units are joined, the slit will be closed.
D. - Now, hold up the triangular flap just above the pocket you have used and insert the flap into a new unit.
E. - Join the right flap of this new unit into the pocket at the back of the unit to the right.
F. - Moving to the right, find the next face with its slit.
Pyramids 12 to 15 - Units 22 to 25
This pattern should be repeated four more times as we move, always towards the right, constructing this third row of the icosahedron.
Result: We have used five units to complete five more pyramids and our third row.
4.4. Row 4
Row 4 will have the last 5 pyramids added, using 5 units.
construction of the fourth row may be seen as a combination of the second and third rows.
You may start at any existing face and work towards the right in a circular fashion.
To sum up this final row, we will be adding 2 units, add 1 unit, join, add 1 unit, join, add 1 unit, join, close last flaps.
Pyramid 16 - Units 26 and 27
A. - Choose any one of the five faces that now make up the top of your model.
We will call this unit 25. It will have a pocket on the right and a flap on the left.
B. - Insert the left flap of a new unit 26 into the pocket of unit 25.
C. - Find the flap of unit 25 and hold it up for the next step.
D. - Insert this flap into the pocket of the new unit 27.
E. - Now, bending unit 27 slightly to the right, insert it into the pocket at the back of unit 26.
Pyramid 17 - Unit 28
A. - Like before, just to the right of the pyramid you have just added, you will find a slit with a flap just next to it that is situated sideways.
B. - Insert the point of this flap into the pocket towards the left. These two elements, namely the pocket on the left and the flap on the right, will already be adjacent to each other, so the join should feel quite natural and obvious.
- Once the units are joined, the slit will be closed.
C. - Now, hold up the triangular flap just above the pocket you have used and insert the flap into a new unit 28.
D. - Join the right flap of this new unit into the pocket at the back of the unit to the right.
E. - Moving to the right, find the next face with its slit.
Pyramid 18 - Unit 29
Repeat the previous step, adding unit 29 to your construction.
Pyramid 19 - Unit 30
Repeat the pattern of closing the slit and adding unit 30.
5. Closing the Icosahedron
Pyramid 20
At this point you should have added all 30 units. All that remains is to close the structure. Turn it so that the central starting point is at the bottom of the shape. You should have 4 loose flaps at the top opening of the model, which will form a final pyramid.
Before continuing, gently reach inside the figure and bring all the flaps so their points lay on the outside surface of the model. Be careful not to dislodge any of these flaps at this time.
Carefully press the figure closed so that the remaining flaps will overlap each other. Your icosahedron will now have taken on its final shape, but with 4 flaps that still need to be tucked in. There should be no more open edges, holes or spaces. You will now be able to recognize where each of the 4 flaps should be tucked into their respective pockets.
- Take any one of the flaps and tuck it into its corresponding pocket. You might need a fingernail to open the pockets of the units now. You can bend the units near the top of the shape very slightly to help with the insertion of these last points, but be careful not to dislodge units lower down around the model.
- Repeat with the remaining 3 loose points. The last flap may feel a little difficult to insert, but just take your time.
Once the last flap slots into place, you will be able to check your icosahedron for any flaps that have not been tucked in, or those that may have dislodged themselves and for obvious places where the shape may not have formed properly. If all went well, you can now appreciate the beauty and symmetry of this amazing geometric shape.
If you are not happy with your result, remember it will take time to master this type of modular origami, so you may have to fold this shape multiple times before you will succeed. Good luck and happy folding!
6. Summary of 30-Unit Construction
You will need 30 Sonobe units folded from square paper.
Row 1
Construct pyramid 1 using 3 units.
Add units 4 and 5 to make pyramid 2.
Add units 6 and 7 to make pyramid 3.
Add units 8 and 9 to make pyramid 4.
Join units 1 and 9 and add unit 10 to make pyramid 5.
Total: 10 units
Row 2
Choose any face with a pocket and a flap.
Add 2 units to make a new pyramid.
Total: 12 units
Each time moving to the right, repeat the previous step 4 more times.
Total: 20 units
Row 3
Join any two units that are right next to each other and add 1 unit.
Total: 21 units
Repeat the previous step 4 more times.
Total: 25 units
Row 4
Choose one of the five flaps and build a pyramid using two units.
Total: 27 units
Join a unit from the right and add another unit.
Total: 28 units
Join a unit from the right and add another unit.
Total: 29 units
Join another unit from the right and add the last unit.
Total: 30 units
Close the remaining points.
Making origami accessible through text-only instructions.
For non-commercial use only.
Compiled by Lindy van der Merwe and Nishi Sakpal - May 2025
This text copyright 2025 by accessorigami.com
accessorigami.com
This tutorial is divided into the following sections:
1. Introduction
2. Terms Used
3. Tips for Constructing the Icosahedron
4. Construction
4.1 Row 1
4.2. Row 2
4.3. Row 3
4.4. Row 4
5. Closing the Icosahedron
6. Summary of 30-unit Construction
1. Introduction
The icosahedron is one of the five Platonic solids, the others being the tetrahedron, the cube, the octahedron, and the dodecahedron.
You can read more about these fascinating geometric shapes at
Cuemath
There are many ways to construct these and other geometric shapes, with and without using glue or tape. In this tutorial, 30 Sonobe units
are used to construct an icosahedron.
For text-based information on how to fold the Sonobe Unit, visit
accessorigami.com
It’s suggested to at least complete structures of 3 and 6 units before moving on to 30 unit assemblies, as experience is valuable for more challenging modular assemblies. You will likely need a lot of time, patience, and some tenacity. It’s normal to grapple with constructions and return to them later. Understanding the concepts in this type of construction and developing fine muscle movement and memory will allow you to eventually construct geometric structures with ease. If you have folded the Sonobe octahedron, many of the concepts used in this tutorial will be familiar to you.
Apart from their beauty and the challenge of construction using origami, hollow, round geometric shapes are also great to use as decorations and as closed containers to present as gifts with something inside (if you don't mind your construction being disassembled by the recipient, that is).
Before continuing, take time to fold at least around 40 to 50 Sonobe units that all look the same.
Important: For each unit, add a diagonal crease from top left to bottom right. Fold it back and forth once or twice without overdoing it to maintain springiness.
If you would like to start with construction immediately, you can now skip to Section 4.
2. Terms Used
2.1. Icosahedron
One of the five Platonic solids with 20 equilateral triangular faces, 30 edges, and 12 vertices. Picture the icosahedron as a round object with fairly blunt points sticking out from its surface. You will shape the model from the bottom, working in a circle from a center point, widening, and ending at another center point at the top.
2.2. Units
In this tutorial, 30 Sonobe units are used to create the icosahedron.
2.3. Flap
Each unit has two points or flaps to be inserted into pockets of other units.
2.4. Pocket
The central area of each Sonobe unit has two pockets where the flaps of other units will be inserted.
2.5. Face
The outside of a geometric structure. E.g. for a cube, you'll see 6 flat square faces, while for the icosahedron, 20 bent triangular faces. While construction is taking place, the faces will appear as diamond or triangular shapes with slanting sides or edges with flaps and pockets.
2.6. Edge
While assembling, will have edges. This is what we will feel if we trace the outline of a unit or a structure.
2.7. Pyramid
The model is made by constructing "pyramids"—triangular shapes that stand out from the model’s surface.
Keep in mind that for this model, each pyramid is formed where 3 units slot together.
There will be 20 pyramids and 30 units.
So, don't be confused by the figures in the instructions below. It will make sense as you proceed with the assembly.
2.8. Orientation
- Working orientation
How you hold your model while inserting flaps, sometimes involving holding it in the air or placing it down temporarily. The "inside" of the structure faces you.
Flat orientation
Primarily used in the beginning stages of construction, the assembly is turned with its inside facing the table, opened and pressed flat. In this orientation, it’s easier to count pyramid structures as they stand up from the model’s flat surface. Ensure all pointy flaps are tucked in underneath the model when in the flat orientation.
3. Tips for Constructing the Icosahedron
3.1. Paper Choice
Use paper around 6 x 6 inches with a rough texture. The paper should be rigid enough to hold its shape. Consider using very thin cardstock, thick construction paper or even braille paper.
3.2. Prepare Units
Fold enough units before starting assembly. It's suggested to fold double the amount needed. This helps with orientation, especially for beginners.
3.3. Accurate Folding
Fold as accurately as possible. Any slight misalignment in points and edges can cause problems during assembly.
3.4. Glue and Tape
Once practiced, no adhesive is needed. However, beginners may find glue or some kind of tape helpful while learning to construct the model. Be cautious, as glue or tape can make adjustments dificult and messy.
3.5. Unit Quality
If units are torn, tacky, or flat, start over with new ones. Compromised units can cause the model to lose shape and fall apart.
3.6. Springy Units
Ensure units feel springy. They should resemble an origami bird with wings open at a 45-degree angle.
3.7. Uniform Folding
Ensure all units are folded similarly, with pockets on the central square faces.
If you omit tucking in the corners to lock the units before turning them over, you will find only a flat surface, with no pockets to use.
3.8. Marking the Center
Mark the bottom center point of the shape. Beginners may find it helpful to secure this point with glue tack for better orientation during assembly.
3.9. Work Area
Use a large tray with a small rim or a flat lid of a box. Keep units on one side and work on the model on the other.
3.10. Organize Units
Keep units in a container and take them out in groups.
3.11. Keep Count
Keep track of the units you insert and those remaining to better understand the row construction.
3.12 Follow Instructions
Do not insert any points other than those specified in the instructions, even if frustrated.
3.13. Diagonal Fold
Ensure all Sonobe units have a diagonal fold across the square. This is necessary for the tetrahedron, octahedron, and icosahedron.
4 CONSTRUCTION
4.1. Row 1
Row 1 will have 5 pyramids radiating from a center point and will need 10 units. Think of it as a bowl-like formation with a small central hole surrounded by 5 pointy pyramids. The construction starts from the left and moves to the right in a circular shape.
Pyramid 1 (First Half Cube) - Units 1, 2 and 3
Summary: Start with unit 1, add unit 2, add unit 3, join unit 1 at the back of unit 3.
A. - Hold your first Sonobe unit with pockets facing away, flaps at the top and bottom. Let the bottom flap rest on the table.
B. - Hold unit 2 with flaps left and right, insert it into the right pocket at the back of unit 1. Hold them together.
C. - Take unit 3, hold with flaps top and bottom, coming from above, insert the flap of unit 3 into the back of unit 2.
D. - Bend unit 1 slightly right, insert it into the pocket at the back of unit 3. You should have a half cube with 3 connected square panels and 3 loose flaps.
E. - Fold in all flaps to lay flat against the inside sides of the half-cube.
F. - Reinforce Pyramid 1 by turning the assembly with the open side on the table (flat orientation). You should feel a point standing up at the center. Press down to accentuate diagonal lines while flattening outer edges on the table.
Note 1
A. Identifying faces Make sure you can identify the 3 faces of your pyramid in this orientation. One will be nearest you, another will be on the right and the last will be on the left. The faces will still be square, but they will now be in a diamond-like orientation with one part of each face standing up, forming the actual pyramid and the other part of each face will form a triangular point that is flat on the table.
B. Identifying edges with pockets and flaps Trace the pyramid outline. It is six-sided. The face nearest you will have an open edge with a pocket on the right and a pointy flap on the left. This pattern is the same for the remaining faces.
G. - Pick the pyramid up and turn it so it is in the working orientation again.
Pyramid 2 - Units 4 and 5
Summary: Add unit 4, add unit 5, join unit 5 on the right with unit 4.
A. - Hold the structure in the working orientation and choose any open edge with its pocket. Turn the figure so the chosen pocket is facing away from you and so you can access it from the right. We will call this unit 3.
B. - Hold unit 4 with its flaps on the left and right and insert it into the right pocket at the back of unit 3.
C. - Find the flap of unit 3, which should be standing up just to the left of unit 4. Hold it up, ready for the next step.
D. - Take unit 5 and, holding it with its flaps at the left and right, insert the flap of unit 3 into the back of unit 5.
E. - Now, bending unit 5 slightly to the right, insert it into the pocket at the back of unit 4. Once done, you will still have a structure that looks a bit like a lopsided cube.
F. - Keeping the points tucked against the inside of the figure, turn the assembly with its open side to the table. Carefully spread the model so that you can feel the pyramid shapes standing up. You should now feel 2 points standing up at the center of the structure. There should be one nearest you and another furthest away, with a straight line separating them, like a valley.
G. - Pinch the new point between your fingers while pressing down on the structure, so that you can accentuate the diagonal lines of the model. Press down as much as the structure will allow. You want the outer edges of the figure to lie flat on the table. Look at the outline of your assembly. If you trace your finger around the shape, you will now find 8 outer edges, or 4 faces, each with a pocket and a flap.
H. - Note the face nearest you, on the right of the structure. You are specifically looking for the open edge with its pocket, since this is where you will be inserting your next unit. Once you find the diagonal opening of the pocket, keep hold of it when you turn the model over.
I. - Like you did before, turn the assembly back into the working orientation and place the figure so you are able to access the pocket you are holding, coming from the right.
Pyramid 3 - Units 6 and 7
Summary: Add unit 6, add unit 7, join unit 7 on the right with unit 6.
A. - Make sure your assembly is in the working orientation with the flap you identified in the previous step on the far right. Alternatively, just hold the structure in the working orientation and choose any open edge with its pocket. Turn the figure so your chosen edge with its pocket is facing away from you, so you are able to access this pocket coming from the right. We will call this unit 5.
B. - Hold unit 6 with its flaps on the left and right and insert it into the right pocket at the back of unit 5.
C. - Find the flap of unit 5, which should be standing up just to the left of unit 6. Hold it up, ready for the next step.
D. - Take unit 7 and, holding it with its flaps at the left and right, insert the flap of unit 5 into the back of unit 7.
E. - Now, bending unit 7 slightly to the right, insert it into the pocket at the back of unit 6. You will find that your model is becoming longer, forming a kind of semi-circle now.
F. - Keeping the points tucked against the inside of the figure, turn the assembly with its open side to the table. Carefully spread the model so that you can feel the pyramid shapes standing up. You should now feel 3 points standing up at the center of the structure. Turn the shape so that one of the pyramids is nearest you with another behind it and the third should be furthest away from you - almost as if the 3 pyramids form a little train.
G. - Pinch the new point between your fingers while pressing down on the structure, so that you can accentuate the diagonal lines of the model. Press down as much as the structure will allow. You want the outer edges of the figure to lie flat on the table. Look at the outline of your assembly. If you trace your finger around the shape, you will now find 10 outer edges, or 5 faces, each with a pocket and a flap.
H. - Note the face nearest you, on the right of the structure. You are specifically looking for the open edge with its pocket, since this is where you will be inserting your next unit. Once you find the diagonal opening of the pocket, keep hold of it when you turn the model over.
I. - Like you did before, turn the assembly back into the working orientation and place the figure so you are able to access the pocket you are holding, coming from the right.
Pyramid 4 - Units 8 and 9
Summary: Add unit 8, add unit 9, join unit 9 on the right with unit 8.
A. - Turn the figure so your chosen edge with its pocket is facing away from you, so you are able to access this pocket coming from the right. We will call this unit 7.
B. - Hold unit 8 with its flaps on the left and right and insert it into the right pocket at the back of unit 7.
C. - Find the flap of unit 7, which should be standing up just to the left of unit 8. Hold it up, ready for the next step.
D. - Take unit 9 and, holding it with its flaps at the left and right, insert the flap of unit 7 into the back of unit 9.
E. - Now, bending unit 9 slightly to the right, insert it into the pocket at the back of unit 8. You will find that your semi-circle is becoming even longer now.
F. - Keeping the points tucked against the inside of the figure, turn the assembly with its open side to the table. Carefully spread the model so that you can feel the pyramid shapes standing up. You should now feel 4 points standing up at the center of the structure. Turn the shape so that one of the pyramids is nearest you. There will now be a train of 3 pyramids behind the first.
G. - Pinch the new point between your fingers while pressing down on the structure, so that you can accentuate the diagonal lines of the model. Press down as much as the structure will allow. You want the outer edges of the figure to lie flat on the table. Look at the outline of your assembly. If you trace your finger around the shape, you will now find 12 outer edges, or 6 faces, each with a pocket and a flap.
H. - Find the place where there seems to be a triangular cut-out or gap when you trace the outer edge of the figure. Rotate the shape so that the gap is nearest you. In the next steps, we will be closing the gap you have identified, which will complete the bottom row or base of our icosahedron.
I. - Now, gently take the figure on both sides and flip it over, away from you, so that the triangular gap is now on the side furthest away. Tuck down all the flaps you can find so they are flat against the inside of the shape. Your assembly is once again in the working orientation, but now it will look more like a bowl with 4 hollow compartments or divisions.
Pyramid 5 - Unit 10
Summary: Join units 1 and 9, add unit 10 and tuck it into the unit to its right.
A. - Locate the gap between units 1 and 9 and close it by inserting the flap on the right into the unit on the left. Once the two edges are joined, the gap will be gone. Don't let go of the place where you have joined these two units. You will need the flap of the left unit that is standing up straight for the next step.
B. - Now, take the new unit 10 and hold it with its flaps at the left and right. Insert the point that you are holding from the previous step into the pocket at the back of unit 10.
C. Lastly, tuck the right flap of unit 10 into the pocket on its right. It will feel a bit strange, as if you are bending the unit when you do this. However, once tucked in, your shape will be symmetrical.
Note 2
The base of the icosahedron is now completed.
A. Flat orientation
Turn the model over, but do not press it flat like before. You will have something vaguely resembling an umbrella, with spokes radiating out from a center point. It will actually be a tiny hole, which you should try to keep as small as possible. This will be a nice reference point for you, though. There will be 5 spokes, each ending in a small triangular mountain. If you follow each mountain away from the center and downwards, you will find a square or diamond shape that ends at a point that will touch the table.
B. Working orientation
If you turn the shape back into the working orientation, the inside of the bowl-like figure will comprise a center point with 5 valley-like divisions radiating out to the edges of the figure.
From hereon, you won't have to turn the model over anymore. You will simply be adding units while the figure is in the working orientation.
C. Faces and Edges
Along the outer rim of the bowl-like structure, its edge will not be straight. You will notice a wavy pattern of edges that slope up and down, forming triangular points that will face the ceiling.
These edges are the same flaps and pockets of the faces we were able to feel in the flat orientation. They are now simply viewed from another angle.
Looking at our model so far, we will find 5 faces, each with a pocket and a flap.
Result: We have used 10 units to create a ring of five pyramids in our first row.
4.2. Row 2
Row 2 will have 5 more pyramids added in a circle around the base you have just created, each time using 2 units.
You may start at any existing face and work towards the right in a circular fashion.
--Pyramid 6 - Units 11 and 12
Summary: Choose the pocket of an existing face, add unit 11, add unit 12, join unit 12 on the right with unit 11.
A. - Choose any one of the faces and locate its pocket which will be on the right.
B. - Insert the point of a new unit into the pocket.
C. - Hold up the triangular flap just to the left of your chosen pocket.
D. - Insert this flap into another new unit.
E. Join the right flap of this last new unit into the back of the other new unit, which will be on the right.
Pyramids 7 to 10 - Units 13 to 20
This pattern should be repeated four more times as we move, always towards the right, constructing this second row of the icosahedron.
Result: We have used 10 more units to complete five more pyramids and our second row.
4.3. Row 3 -
Note 3
construction of the third row may be seen as a combination of the first and second rows.
You may start at any existing face and work towards the right. So, we will be joining two existing units and add a new unit, repeating this pattern 4 more times.
This row could also be likened to the formation of five tables or ledges, since we are now closing or pulling our structure together and towards the closing point at the top.
Your construction will be more elaborate now, but it will still seem floppy, as if it may fall apart at any moment. Things will look much better after you have added five more units in this row.
Looking at the faces of your model now, they will each have a pointy flap on the right with an open edge on the left. If you follow this open edge downwards to the left, you will find an opening resembling a slit, with a flap that seems to lay sideways. You will be joining this flap to the left, so it will close the slit or gap that has formed between the five parts making up the circular structure.
Pyramid 11 - Unit 21
Summary: Locate the slit and sideways flap, join the flap into the pocket to close the slit, lift up the flap just above the pocket you have just used and join it to the back of a new unit; join the right flap of the new unit to the right.
A. - Choose any one of the faces and locate its open edge which will be on the left.
B. - Follow the edge to the left and downwards until you find a slit with a flap just next to it that is situated sideways.
C. - Insert the point of this flap into the pocket towards the left. These two elements, namely the pocket on the left and the flap on the right, will already be adjacent to each other, so the join should feel quite natural and obvious.
- Once the units are joined, the slit will be closed.
D. - Now, hold up the triangular flap just above the pocket you have used and insert the flap into a new unit.
E. - Join the right flap of this new unit into the pocket at the back of the unit to the right.
F. - Moving to the right, find the next face with its slit.
Pyramids 12 to 15 - Units 22 to 25
This pattern should be repeated four more times as we move, always towards the right, constructing this third row of the icosahedron.
Result: We have used five units to complete five more pyramids and our third row.
4.4. Row 4
Row 4 will have the last 5 pyramids added, using 5 units.
construction of the fourth row may be seen as a combination of the second and third rows.
You may start at any existing face and work towards the right in a circular fashion.
To sum up this final row, we will be adding 2 units, add 1 unit, join, add 1 unit, join, add 1 unit, join, close last flaps.
Pyramid 16 - Units 26 and 27
A. - Choose any one of the five faces that now make up the top of your model.
We will call this unit 25. It will have a pocket on the right and a flap on the left.
B. - Insert the left flap of a new unit 26 into the pocket of unit 25.
C. - Find the flap of unit 25 and hold it up for the next step.
D. - Insert this flap into the pocket of the new unit 27.
E. - Now, bending unit 27 slightly to the right, insert it into the pocket at the back of unit 26.
Pyramid 17 - Unit 28
A. - Like before, just to the right of the pyramid you have just added, you will find a slit with a flap just next to it that is situated sideways.
B. - Insert the point of this flap into the pocket towards the left. These two elements, namely the pocket on the left and the flap on the right, will already be adjacent to each other, so the join should feel quite natural and obvious.
- Once the units are joined, the slit will be closed.
C. - Now, hold up the triangular flap just above the pocket you have used and insert the flap into a new unit 28.
D. - Join the right flap of this new unit into the pocket at the back of the unit to the right.
E. - Moving to the right, find the next face with its slit.
Pyramid 18 - Unit 29
Repeat the previous step, adding unit 29 to your construction.
Pyramid 19 - Unit 30
Repeat the pattern of closing the slit and adding unit 30.
5. Closing the Icosahedron
Pyramid 20
At this point you should have added all 30 units. All that remains is to close the structure. Turn it so that the central starting point is at the bottom of the shape. You should have 4 loose flaps at the top opening of the model, which will form a final pyramid.
Before continuing, gently reach inside the figure and bring all the flaps so their points lay on the outside surface of the model. Be careful not to dislodge any of these flaps at this time.
Carefully press the figure closed so that the remaining flaps will overlap each other. Your icosahedron will now have taken on its final shape, but with 4 flaps that still need to be tucked in. There should be no more open edges, holes or spaces. You will now be able to recognize where each of the 4 flaps should be tucked into their respective pockets.
- Take any one of the flaps and tuck it into its corresponding pocket. You might need a fingernail to open the pockets of the units now. You can bend the units near the top of the shape very slightly to help with the insertion of these last points, but be careful not to dislodge units lower down around the model.
- Repeat with the remaining 3 loose points. The last flap may feel a little difficult to insert, but just take your time.
Once the last flap slots into place, you will be able to check your icosahedron for any flaps that have not been tucked in, or those that may have dislodged themselves and for obvious places where the shape may not have formed properly. If all went well, you can now appreciate the beauty and symmetry of this amazing geometric shape.
If you are not happy with your result, remember it will take time to master this type of modular origami, so you may have to fold this shape multiple times before you will succeed. Good luck and happy folding!
6. Summary of 30-Unit Construction
You will need 30 Sonobe units folded from square paper.
Row 1
Construct pyramid 1 using 3 units.
Add units 4 and 5 to make pyramid 2.
Add units 6 and 7 to make pyramid 3.
Add units 8 and 9 to make pyramid 4.
Join units 1 and 9 and add unit 10 to make pyramid 5.
Total: 10 units
Row 2
Choose any face with a pocket and a flap.
Add 2 units to make a new pyramid.
Total: 12 units
Each time moving to the right, repeat the previous step 4 more times.
Total: 20 units
Row 3
Join any two units that are right next to each other and add 1 unit.
Total: 21 units
Repeat the previous step 4 more times.
Total: 25 units
Row 4
Choose one of the five flaps and build a pyramid using two units.
Total: 27 units
Join a unit from the right and add another unit.
Total: 28 units
Join a unit from the right and add another unit.
Total: 29 units
Join another unit from the right and add the last unit.
Total: 30 units
Close the remaining points.
Making origami accessible through text-only instructions.
For non-commercial use only.
Compiled by Lindy van der Merwe and Nishi Sakpal - May 2025
This text copyright 2025 by accessorigami.com
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