I think that is what they're called
Anybody know where I can buy them. Its really masking tape in small circle shapes of about 2-3 mm dia.
I use them on holes in PCBs to stop solder blocking up holes with solder when they were put through the soldering machines.
Usually they are on a roll of waxed paper.
I will be useing them to cover the glass part of the porthole when I spray the frames.