i you do use paint, i would reccommend tamiya model paints, they are some of the best quality that i have seen and used and they dry very quickly. also use a very very fine brus, like only a couple strands for detail work. i will be the first to admit, i suck at painting, but the lego stuff i have painted came out pretty well. just take your time with it as well.
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I paint in details on my Minifigs, but I generally keep it simple because this seems to work best. I've never tried painting bricks in solid colour though and I'd have my doubts about this unless it's a MOC that's going to be a permanent assembly.
Paint is only good for detail work on surfaces that aren't going to connect together. If you want to change the color of a whole construction element, vinyl dye is the correct solution:
Zahru II wrote:As a purist I'm terryfied even of the thought of painting bricks, but I suppose your best bet would be that kind of paint that can be easily removed (acrylic? idk).
One thing that I tried was using masking tape and putting them on minifigs then coloring the masking take with a permanent marker it worked pretty well and can be used to make lots of different minifigs seem similar.
Only 2 things are infinite the universe and human stupidity, and I'm not so sure about the former- Albert Einstien.