Credits and Resources
Text-Only Tutorial - Copyright 2026 by Lindy van der Merwe
accessorigami.com
This model by Sam Ciulla is based on the video
Stellated Octahedron by James Peake of Foldspace Origami Studio
A diagram is available at
instructables.com
For other places of publication, you can also see the following page on Gilad's Origami:
GiladOrigami.com - Designer - Sam Ciulla
For more about the geometric figure, visit
wikipedia.org - Stellated_octahedron
Paper to be used: A square of around 15 x 15 cm or larger - thicker paper or thin card stock is strongly recommended.
You can try to use copy or printer paper or even braille paper should work well for this model.
Folding level: Beginner to Intermediate
Remarks:
It is suggested you read through this entire tutorial before starting to fold. This will give you an overview of how the model will be constructed so you will know what to expect.
This figure makes a nice hanging decoration.
To use as a container, small objects can be added before the figure is closed and inflated.
Description
As might be expected, there are many types of octahedra and as many ways of folding them, not to mention that variations of them all keep surfacing constantly. If you have delved into the realm of modular origami, you will know that the octahedron from 12 Sonobe units is one of the more well known geometric creations. This stellated octahedron by Sam Ciulla is folded from just one square, though. It uses some basic techniques, including folding a grid, adding diagonal lines, collapsing the paper into a slightly modified Waterbomb Base and then completing the model by making a fold, tucking in a flap into a pocket and lastly, it is inflated, just like the original Waterbomb Based models like the cube or balloon, but unlike these models, the stellated octahedron will not have a flat surface. It will show the characteristic pyramid shapes of the octahedron. The more pointy shapes are formed by extending of the octahedron faces into pyramids or it can also be considered to be the compound of two tetrahedra.
Each of its 8 points are made up of 3 triangular faces (see Part 4 below for more information).
Please feel free to contact accessorigami@gmail.com for any feedback, help or suggestions.
The tutorial is divided into four parts:
Part 1 explains all the pre-creases to be made in detail.
In Part 2, the corner folds and collapse is described, and
Part 3 explains how to close and inflate the octahedron.
Part 4 contains an extended Description by Gemini 3 as well as a tip for sharpening the various creases of the stellated octahedron.
Instructions:
PART 1 – PRE-CREASES
Making strong and accurate pre-creases is especially important for this model, since it relies on various mountain and valley folds to cross/intersect at exact points for the folding process and inflation to be successful.
Step 1 - THE GRID
We will first form a grid of 16 squares, which will all be formed by making vertical and horizontal valley folds.
You can perform these pre-creases in any way you prefer, as long as all of them end up being valley folds on the side of the paper you have chosen for the outside of the octahedron.
So, You will position the square colored side up, with its edges at the top and bottom and on the left and right.
Perhaps the easiest and most accurate way would be to make a book fold, followed by a cupboard fold. Unfold the square and rotate it 90 degrees. Then repeat the book and cupboard folds. Unfold.
Some people find it easier to fold an edge away from them, so you can just as well fold the top and bottom edges of the paper instead of folding from left to right.
Result: You should end up with a square that has been divided into 16 small squares or with the crease lines forming a 4 by 4 grid.
Step 2 - THE DIAGONALS
Flip the square over so the "white/inside" surface is facing up and rotate your square into the diamond orientation, with one of its points facing you.
2.1 Location of crossing points
We are first going to locate the following crossing points or intersections on our grid and mentally number them as indicated:
Intersection A: Starting from the point nearest you, follow the vertical line that stretches to the opposite point of your diamond shape. Find the first place where this line intersects with other diagonal lines. This is Intersection A.
Intersection B: Move along the same vertical line, away from you. The next crossing point you find will be Intersection B.
Intersection C: If you continue in the same direction as before, you will find the furthest and last intersection of creases, Intersection C.
2.2 Folding with the first corner
We will now make three folds using the same corner of the diamond shape, the one that is nearest us.
at the moment.
(A) Fold the corner or point in question away from you so it meets Intersection A. Make a strong crease along the fold and then unfold.
(B) Now, take this same point and fold it upwards to Intersection B. Crease well and unfold.
(C) Lastly, fold the point to meet Intersection C, creasing and unfolding.
Result: We have formed three new crease lines with one of the corners of our square.
2.3 Folding with the remaining three corners
Rotate your square to the right or clockwise so you have the next/second corner nearest you.
Repeat the 3 folds from the previous step with this point.
Rotate to the third corner and make the three folds as before; then repeat the three folds with the last/fourth corner of the diamond/square.
Result: All your diagonal folds are completed.
In fact, all the precreases are done. You have formed 16 blocks on the colored side of the square with the diagonal creases on the opposite/white side of the paper.
You can perform a check to make sure you have completed each crease by turning the open square paper so one of its edges is horizontal again.
Each of the 16 squares should have two diagonal lines crossing each other, or forming a print letter X in each of them.
Part 2 - Corner Folds and Collapse
Apart from forming the precreases, folding in the four corners of our square is a small, but important, modification we have to make to the Waterbomb Base for this model to work.
Step 3: Corner Folds
With the paper positioned in the diamond orientation again, white side up, fold in the corner nearest you to Point A. You are refolding or just repeating Step 2.2 A. Another way to think of this fold is that you are folding each corner square of the model in half.
Rotate the diamond shape to the right three times, each time folding in a corner, so all four corners are folded over.
Result: You will now have an eight-sided shape with four long edges and four short edges.
Step 4: Collapse
We are ready to collapse our paper into the Waterbomb Base. To do this, first flip the paper over to the colored side again. Rotate it into the diamond orientation and refold the diagonal lines from corner to corner so that you can collapse the paper into the Waterbomb Base in the "normal" way, by grasping the left and right corner points and bringing them together.
It may be helpful to imagine the square as if the corners were not folded in or you can unfold the corners, collapse the square and refold the corner points again.
Result: You should now have the modified Waterbomb Base flat on the table with two flaps on each side. Instead of the points you would normally have, which would have a triangular outline, you will now have a five-sided outline. In this flat orientation, simply think of the shape as having three long sides and two short sides, the latter caused by the folded in corners.
Part 3 - Closing and Inflating the Model
Step 5
This step has 3 parts, namely two folds and a tuck of the paper into a pocket.
Keep in mind you are going to work with the front layer of the Waterbomb Base only. Later, we will turn the shape over and work on the remaining side.
5.1 Fold Left: Locate the bottom long edge of the flat five-sided shape. Investigate the crease lines on the surface of the folded shape with your finger. You want to find two square blocks, at the center of the shape, near its bottom edge.
Find the left square and place a finger on the center of the X shape, where the diagonal lines cross within this left square.
This is the exact spot you will need to aim for when making your fold.
Now, with your other hand, notice that you have two points at the right corner of the overall shape. Let's call them the "upper" and the "lower" right points.
take the lower right point of the overall shape and fold it to the left and slightly upwards, so it comes to rest exactly on the spot you have located. Make a strong fold along the right edge of the shape.
The angle of this fold is very important, so try to make this fold as accurate as you can.
Result: You will now have a double-layered four-sided shape laying on top of the model, consisting of a long, straight edge on the right; on the left there will be two slanting sides, leading down to a very short edge of the four-sided shape. This edge should lie horizontally, along the bottom straight edge of the larger model.
5.2 Fold right: You are now going to locate the left point of the four-sided shape, where the two diagonal sides meet. Take this point and fold it straight to the right, using the existing vertical fold created in earlier steps. Once flipped/folded over, the point will just touch the right, long edge of the four-sided shape.
You have now formed a new triangle on top of the other layers of the model, with its base on the left and its pointy end to the right.
Important: The sloping side of this triangle, nearest you, is also a pocket you will use in the next step.
5.3 Fold Up and Tuck: Now, focus on the bottom right corner of the four-sided shape. You will find a very small, movable triangular flap. Take this flap and fold it upwards and inwards as far as it will go. It will be stopped by the flap you created in 5.2 above.
Finally, unfold the small flap and, opening the pocket of the triangle you formed in 5.2, tuck it securely inside.
Result: The right side of the modified Waterbomb Base will now be tightly folded closed.
Step 6
Repeat Step 5 in the opposite direction with the front left corner of the model.
This time you will not have a square with a cross to aim for. Instead, fold the lower left point of the shape over so it touches the pointy end of the triangle that has formed on the right.
Result: This side of the model will now have a tall six-sided outline with various triangles that has formed. The structure has various layers and what seems to be a vertical slit, but this side of the model is now entirely closed in.
Step 7
Flip the entire model over from left to right.
Starting on the right, repeat Step 5; then using the left corner, repeat Step 6.
Result: You will now have a flat, but multi-layered six-sided shape, forming a completely closed structure, except for a small hole at the end nearest you, or the opposite end of the original closed point of the Waterbomb Base.
Step 8
Lastly, very slightly unfold the flat shape so the air has space to move. Lightly hold the model by the sides and blow into the small opening nearest you.
The folded shape should puff out into a ball-like structure characterized by various triangular pyramids formed on its surface.
You may have to pinch and poke the various valley and mountain folds so they form the neat geometrical shape of the stellated octahedron.
See Part 4 below for more info and a tip for sharpening the creases of the finished model.
Don't be alarmed or discouraged if your model ends up lop-sided or misshapen when folding it for the first time.
It is completely normal for it to feel a bit "soft" or rounded the first few times you make it; achieving those razor-sharp points requires very firm pre-creasing to ensure perfectly crisp lines after inflation.
Part 4 - Extended Description - Gemini 3
For those interested, the text below is a description by Gemini 3 of the finished model. It described the folding of this model perfectly, except for the folds in Part 3, for which I had to consult with a human, who took 3 minutes to watch the part of a video showing Steps 5 and 6.
"Text from chat with Gemini 3 app - https://gemini.google.com/app - 1 January 2026.
Based on Sam Ciulla's design, here is the breakdown of the shape you should be feeling so you can verify your "Stellated Octahedron" (also known as a Stella Octangula or eight-pointed star).
1. The 8 Points (The Peaks)
These can be described as 8 triangular pyramids (spikes) pointing outward.
The Structure: Each point is a pyramid with 3 triangular sides.
The Tips: If you feel the very tip of any "spike," you should feel 3 edges meeting at that one sharp point.
The Arrangement: If you hold one point between your thumb and forefinger at the "top" and another at the "bottom," you should feel 3 points arranged in a ring around the top one and 3 points arranged in a ring around the bottom one.
2. The 6 Valleys (The "Craters")
The Location: These valleys are located exactly between the spikes.
The Structure: Each valley is a "dimple" where 4 edges meet at the deepest point.
The Geometry: These 6 deepest points actually represent the corners of a regular octahedron that is "hidden" inside the spikes.
3. The Faces and Edges
Triangles: If you run your finger over the surface, the entire model is made up of 24 small triangular facets. (Each of the 8 spikes has 3 visible triangles).
The "Equator": If the model is sitting flat, you might notice a slight "belt" or horizontal line where the paper was folded into the waterbomb base, but in a perfect version, this is hidden by the symmetry of the spikes.
4. Overall Symmetry
A perfectly folded stellated octahedron fits perfectly inside an imaginary cube.
If you imagine a cube, the 8 tips of your origami spikes would touch the 8 corners of that cube.
This means the model should feel very balanced. No matter which point you turn to the top, it should look and feel the same.
5. Tip: How to sharpen creases:
1. Locate one of the craters or dimples, where 4 edges meet at the deepest point on the surface of the model.
2. Follow the "ridges" (the mountain folds) that lead from that crater up to the tips of the nearby spikes.
3. Pinch those ridges firmly between your thumbnail and finger.
4. Sharpening these 36 ridges (the lines connecting the peaks to the valleys) will make the model pop into a much more rigid, geometric shape."
Making origami accessible through text-based tutorials.
For non-commercial use only.
Compiled by Lindy van der Merwe, January 2026
This text copyright 2026 by accessorigami.com and the author.
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