After you have applied the stained glass to the sticky side of the clear contact cement you are ready to grease the mold and position the glass. You can spray with PAM or use Vaseline. Coat the inside of the mold liberally without leaving globs. Gently press the glass into the bottom of the mold so that you have a good seal. You are trying to avoid having cement get behind the contact cement. After this step you will be ready to mix your cement and pour your stained glass stepping stone.
The widget below features diamondcrete, stained glass patterns and a nice program for resizing patterns called rapid resizer.