Thanks to both of you. Another question, is it worth buying the proprietary thinners/retarders/flow aids or does distilled work the same, better, worse?
Distilled or tap water will reduce the pigmentation of your paint, which in such small scale (and if you use only a little to just thin it a bit … not too much, and always on a palette, not in the bottle) is not a big deal.
If using water, definitely go easy on it. Never more than 50/50, but I wouldn’t even go that thin personally. I’d go more with something like 80/20 (Paint/Water).
I REALLY like using Acrylic Matte Medium. It’s a thinner but it maintains the pigmentation of your paint, and it adds a matte finish to it at the same time. YOu can also get Gloss medium if you like the gloss look, but in either case I personally use a Matte varnish on top of all my minis anyway, so matte medium works for me. (Techincal: Acrylic Medium is an Acrylic Polymer Emulsion that is used as the binding agent for acrylic paints, just without any color pigmentation added).
Another decent tip is to make sure each successive coat is just a little THICKER than the previous coat (so you’re starting with very thin and working your way up to that 80/20 mix) and you’ll likely at this scale only want to do a max of 3 coats for your base colors and 1-2 for details and line work.