Hellhounds
Active Hunter
I know people were having a hard time with painting their rubber knees they got from slave1pilot or stormrider and not having them crack. I'm not sure if it was completely solved for what paint is the best but I came across this video on how to paint rubber with a special paint. you can airbrush it on or just straight brush it.
http://www.wonderhowto.com/how-to/v...-rubber-for-special-effects-and-props-157883/
http://www.wonderhowto.com/how-to/v...-rubber-for-special-effects-and-props-157883/