Objects to 3D XOR with other objects to make checked/striped/spotted (even gingham - for picnics) items in two colours

Best utilised when we can get a two colour Candystruder (CandyFab acknowledged). Hey, what about milk and white chocolate...

And, of course, there's tartan for anyone who thought that I was only joking...

Take two STLs, one that you prepared earlier and one XOR stl.

Then use OpenSCAD to create a positive:
difference() {
import_stl("stlNumber1.stl",convexity=15);
import_stl("Check.stl",convexity=15);
}
and export STL.

Create support (or second colour)
intersection() {
import_stl("stlNumber1.stl",convexity=15);
import_stl("Check.stl",convexity=15);
}
and export STL.

Now place in a medium temperature twin 3D printer until golden brown.