whats the best grade

[craigcraig]

how do you know what the best grade of sand or glass bead to use? and when masking a big area off i read on here that using foil helps limit wasting tape. also if you can use the foil with the tape, would blasting go through the foil?

[DALE]

For blasting I mask with Duct tape. It's cheap and holds up well.

[skiddz]

I use duct tape or electrical tape to mask. Foil might hold up if you don't directly blast it. Contact paper will cover large areas and will hold up well under the gun. I used to etch decorative patterns in glass with a sandblaster. I'd cover the glass/mirror with contact paper, cut my design out with an Xacto knife and blast away. Worked great.