I have been using Polly for years. recently I bought a mechanical Tea bag at IKEA. It is a scissors like device with 2 semi round screens. I use it to screen out silod matter from the paint before I pour it into my feed cup.
I have started making my own seals for the lids to replace the battered card stock seals that are on the bottles. I use the seal from my maintenance meds from Express scripts. I suppose if you are in perfect health you could use .10 styrene and cut your own.
I like to keep my pressure at 35 PSI and thin with bottled water. I have used a Pasche H with a #3 tip but have switched to a #5. It's much better and doesn't clog as fast.
At Trainfest I spoke to the Iwata reps and they suggested using anything but Polly. Ufortunately it's more available in my area. The plus side is it does brush quite well and levels nice and flat.
I wash all my cars with Dawn (which now has an extreme formula) spray direct to the models, gloss coat with Future and flat finish with Polly Flat. My cars get handled and I haven't noticed any scratches or chips. Some wear on the brass grabs but I don't blast before I paint so it serves me right.
Rob Manley
Midwest Mod-U-Trak
"Better modeling through personal embarrassment"