Originally Posted by 123pugsy
Never used em. Does paint usually have lumps in it?
Dried crumbs from containers or lids are the most common catch. I like normal pour-through strainers made of paper but an in-cup one is added insurance. As HipG said, too fine can strain out flakes in color. Those ones are for your dedicated clear gun.
I don't have a proper micron answer. Best I can do is say it depends.