Geometric Chrismas Ornament That Folds Flat!

A perfect alternative for a Christmas card. This 3D tree ornament can be used to decorate your home or a christmas tree, and then can be folded flat for easy storage or for sending it to your frieds as a Christmas card. It then easily folds back into a 3D shape.

Choose the radius of your ornament (mine is 4.5 cm) this is represented by r1 in the formula.

Choose the number of layers in your ornament, it has to be an odd number (I recommend 5, though if your making a particularly small or large ornament, you can use fewer or more layers), the number of layers is represented by n in the formula.

Using the formula provided, calculate x - the distance between layers, and the radii of the smaller circles.

On plain paper draw 2 of the largest circles and 4 each of every smaller circle. Draw slits that go half way every x cm. I recommend alternating the orientation of the slits as shown in the picture.

Cut out the circles making the slits around 0.5-1 mm wide (doing it by eye is fine) to account for the thickness of the paper.

Assemble the ornament starting by sliding together the largest circles and then moving in descending order.

Disassemble the mock up and use the circles as templates to cut out circles from the colored or pattern paper (i used hand decorated colored paper, patterns posted here).

Assemble the ornament the same way as you did with tje mock up.

Use a needle to poke 2 holes in one of two largest circles. String through the decorative string and tie the ends