Place cookie cutters on a wax paper-lined baking sheet. Pour half of white chocolate into cutter. Pour half of semisweet chocolate on top, and swirl together with a wooden pick. Repeat process with remaining chocolate. Let stand 4 hours or until completely cool.
Note: For testing purposes only, we used Ghirardelli White Chocolate Baking Bar and Ghirardelli Semi-Sweet Chocolate Baking Bar.