Make a physical Escher print by cutting different parts of a tessellation in different materials.
Step 1: Get image
Get a digital copy of your favorite tessellation either by scanning a paper copy of searching the web.
I chose reptiles.
Step 2: Create CAD file
Convert the image to a vector format.
I converted the jpeg to a tiff and then used Adobe Streamline to convert it from a raster image to a dxf. The dxf was really messy, so I cleaned it up by hand using AutoCAD and cut out everything but a single repeating tile.
Both the raw and cleaned dxfs are in the files section.
Step 3: Remove excess points
Streamline generated too many points, but could not be trusted make good vector files at lower point densities. Knowing that 8 billion points at every corner of the drawing would only slow down the cutting process (or worse, overload the tool's limited memory), I deleted extra points by hand. When three points form a line, delete the middle point. Use your judgement and remove points that are beyond the resolution of the tool.