Once a sketch has been approved, the actual fabrication begins. A life size drawing or cartoon is made from the sketch. This cartoon has two purposes: patterns are cut from it in order to cut the needed glass and acts as a blueprint when leading the window together.

The design determines the type of glass used. Cathedral Crafts uses a variety of imported antique glass from Germany, England, and France, as well as domestic opalescents. Some design will require various pieces of glass to be hand painted. All hand painted work is kiln fired so as to fuse the paint to the glass.