Multicolor layered snap-together coaster

The core of this project is a multi-layer snap-together coaster which can have a top design in several different colors from the different layers. Each layer is printed seperately, and then the result is snapped together. The basic machinery for doing this is packaged as an OpenSCAD module which can take any set of 2D images and make a coaster using their colors. The proof-of-concept I'm working on (still in progress!) is a set of coasters with the 46 counterchange patterns of H.J. Woods.