After a frustrating day of trying to engrave glass using the Cold Galvanizing Compound, I got better results today using only masking tape. No prep time. Very little clean up. If you are looking to engrave glass, this is a must watch. But it's not just the tape. It's the technique. If you don't watch it through to the end, you probably won't get the same results. A long video, but it could save considerable time trying to figure it out yourself. Let me know if this helps or if you have any improvements.