The edges of each piece of glass slide snuggly into the channels of previously shaped lead calme. The next strips of lead are cut to cover exposed edges of the newly added piece of glass. As you can see, I use nails in an unconventional way to secure the glass and lead. This allows the sheet of glass from which the next piece will be cut to lay flat on the cartoon for a more accurate tracing of the shape to be cut. This results in a tighter fit, and a more rigid panel of stained glass.