Has this ever happened to you? You draw a guideline on your glass with a marker, but when you start to grind or saw along that line, the water washes it away! Mark Stay solves this problem. A thin film of non-toxic Mark Stay preserves the line, yet doesn't clog the grinding head. Washes off with soap and water.

While the manufacturer is careful to say it is not a wax, it is actually kind of waxy, and thus can also be used to attach pattern pieces temporarily to glass before grinding.

Comes in a small (1 oz.) jar.