Yesterday I explained the mathematics behind Sugihara’s Circle/Square Optical Illusion, which appears in this video.

Today I created a printable template from which you can make your own version of Sugihara’s object.

Click the following image to download the pdf.

Making the shape and seeing the illusion is easy.

1. Cut out the figure at the top of the page.
2. Fold a sharp crease along the dotted line.
3. Tape the left and right edges together.
4. Fold a sharp crease along the taped seam.
5. Lightly squeeze together the creased sides so that the shape opens. Looking down on the shape it should have the shape at the bottom of the printout.
6. Close one eye. Look down on the shape at a 45 degree angle so that the two creases line up with each other.
7. Then turn it around 180 degrees and look again.