" in environmental terms the aerosol propellant still ends up in the atmosphere, filter or not,"
That's why air brushes are best. Propellant is compressed air 😊 so all the filter has to worry about is the paint particles floating about👍
Using acrylics on a water base also eliminates any nasty solvents getting into the atmosphere.
Snag is finding just the colour you need in acrylic🤔 Although LifeColour are pretty good.
Happy 'emitting' Rob 🙊
Cheers, Doug 😎