Glass Call Conditioning

[Spitten and drummen]

Don't know how true it is and can't remember who the callmaker was. But using drywall screen your fingertips will leave oil on the surface. I always use a stone.

In my opinion I have used everything from stone to sand paper and found the screen works the best. Thats just my preference. I have also found rougher screen from more rasp and finer seems to give me a cleaner sound. To my ears anyway.

[jed clampett]

I use drywall screen...sometimes I go over it lightly with a stone..depends on what sound I want...i go back and forth 9 to 3 3 to nine

[LaLongbeard]

Drywall screen
If you feel like you got oil on the surface you can wipe it off with rubbing alcohol wipe and it will evaporate and be good as new