Almost every can of paint I have used, gets turned upside down after usage and I push the nozzle letting the paint that was still in the tube drain and clear out the nozzle. Those cans that I forget to do this to is heavily subjected to plugging up making it impossible to use next time. Another idea is to after usage pull the plastic nozzle off the can and let it soak in acetone or whatever for a couple minutes followed by some compressed air blown thru.
Craig
My '50 Chevy 3100 5 window, '62-235cu, 3:55 rear
My truck ....... Respect The Rust
If I'm not working on my truck, '65 m00stang or VW camper, I'm fishing with the wife or smoking Salmon.