I used to use filters for my paint.
Nowadays I find there is little need to, and so far, I haven't had any issues.
Touch wood.
Back then the pigments were really muddy, and it took forever to stir the paint up enough to disperse all the sediment.
I used to use really fine mesh filters, here they are sold in tobacco shops, for pipe smokers.
As an alternative, some tap fittings come with in line mesh filters, especially for garden irrigation systems, and the perforations in the filters is extremely fine.
I'm sure someone here may know of a shop or site that sells them for our hobby.
Hope this helps
Sean