If you want to change colors you will have to clean them out.
But what if you’ll spray olive-drab green from the same bottle until cows fly and pigs stop producing bacon? mmmm bacon…I love hickory smoked *ahem* Sorry, I’ll focus now…
If you only want to spray the same color from that particular bottle day-in and day-out you shouldn’t have to continually wash and clean your the bottles.
How to Not Clean
Many airbrush paint bottles come with a little red cap to seal the top hole. When you’re done spraying simply…
Fit the red cap over the nipple
Stick a piece of tape over the vent hole.
If air can’t enter the bottle and the paint’s solvent can’t evaporate your paint should stay nice and, well, paintable!
Three Things to Know
Peel back the tape when you want to spray the contents of that bottle. No clear vent hole = no spray.
Shake the bottle very well before spraying. Be James Bond. Spray your paint shaken, not stirred. If you’re spraying something that can’t settle then don’t worry about shaking, otherwise, always shake up your paint!
Some paints can eat through plastic bottles over long periods of time. Even solvent-proof bottles slowly melt if you leave certain kinds of paint in them. This mostly applies to automotive paints, enamels, and lacquers. Even then, it takes weeks, months, or even years to melt a solvent-proof bottle. Non-solvent proof bottles and solvents are an entirely different matter, they’ll melt in seconds to minutes–it’s actually really kind’ve fun to watch…I mean don’t do it! You’ll get paint everywhere!