I always brush paint, and usually with Tamiya acrylic. So long as it dries properly between coats I've never had a problem, and never had to thin it! How long have you had that jar of paint!

Famous paint is known for being more difficult to hand brush with. While difficult, it is not impossible. Tamiya paint should be thinned anywhere from 30-50% thinner, depending on the color. Thin with their own acrylic thinner, as it has a retarded built into it. Never brush over the same area twice without letting it dry (some people say 24 hours) or else the previous layer will come up in clumps.

Hello Leung Chi Him,

I can't speak for others, but can tell you that I have the same experience as you when brush painting Tamiya acrylics.

I use Vallejo and other brands that work better for brush painting, and Tamiya for airbrush (which works great).

I have the opposite problem med Vallejo: great for brush painting, but I personally have had problems with them when airbrushing. They tend to clog up my airbrush, no matter how much I thin them.

Again, this is just my experience. I know a lot of modellers have great success brush painting Tamiya and airbrushing Vallejo :-)

Cheers,
Sven

No experience on Vallejo, but as I understand Vallejo has a line that's specific for airbrush use (?)