I have been playing with the Fujimoto Cube for a while now and wrote about some variations I created here. Recently, I realized that this origami structure can be applied to an equilateral triangle to make a triangular prism box. Below are the stepouts for this box.

I started with paper that was in a ratio of 3:4 or 6 x 8 inches. After getting the first 60 degree angle drawn in the top and bottom left squares, I trimmed the top and bottom sections as shown in image 4. Then I drew all the other 60 degree angles and scored them all. You do not need to draw any of the red lines shown, just fold or score them except for the first 60 degree angles that need to be drawn in pencil so you can trim. The last image shows the whole process with steps that should make sense with the images I have provided.

I suggest using sturdy paper (cardstock weight or maybe elephant hide paper) for this box. Enjoy!