Hand brushing Model Master Acryl

Generally, they are ready  for brush painting right out of the bottle. They work very nicely with a brush.

 They thin fine with plain water for brush painting. (For airbrushing I use their proprietary thinner or my tip clogs up too quickly)

 Always use a pallet, old bottle cap, pill tray, or whatever to thin and mix paints.  Never add anything to the paint bottle itself.  You may contaminate your paint with something it doesn't agree with and ruin the whole bottle.

I suggest using either tooth picks or tiny straws from a dollar store to transfer paint from the bottle. When dealing with hand brushing you will have paint sitting around for a while while you paint. I like to have a tiny amount and add more as I need it then to have a lot sitting around that will require thinning more often and possibly lead to wasted left over paint. Aside from that dmk said it all. Only difference is I tend to use distilled water (found at a pharmacy).