Thinning humbroll colors

if you airbrush, you'll need to thin Humbrol paints with some sort of mineral spirit. 1/3 thinner 2/3 paint is a good start but practice and practice again 'cause flat paints and glossy paints will need different mix for instance. Humbrol markets its own mineral spirit, but you'll do equally well (and your wallet will feel better) with turpentine or the store brand mineral spirit you can find in any shops such as WalMart.

Ok 10x, now one more question about thinning, heller/any other water colors I can thinn in the same ammount with a usual water? right?

Acrylics (Heller, Humbrol, Tamiya..) are best thinned down with methyl alcohol but water will do too. Add a bit of dish-washing detergent (a drop) to your mix to help break the water' surface tension.

got it