I use Tamiya acrylic thinner for thinning Tamiya paints. They are better than ordinary isopropyl alcohol. To save cost, I only use isopropyl alcohol for general washing off Tamiya acrylics after airbrushing or brush painting.
However, I am gradually switching to Gunze Mr Color(synthetic lacquer based acrylics) paints for airbrushing and Gunze Aqueous Hobby Color(water soluble acrylics) paints for brush painting. Unfortunately, I have amassed a lot of Tamiya acrylics before my switch to Gunze. Gunze paints have far finer paint pigments than Tamiya thus will dry to a thinner and smoother finish compared to Tamiya.
The only other brand which I seldom used, but tested and founded to be as equally superb as Gunze paints, are Vallejo acrylics. It is not so popular in my country for 3 reasons:
1) All their bottle caps are of same standard colour (not color coded!) - white cap for normal acrylics, and black cap for factory pre-thinned airbrush ready acrylics. Even though the bottles are made of translucent PE, it is still difficult to search for colours, except to read the labels.
2) Their colour names seemed more suited/catered towards figurine paintings. So don't expect to find something like NATO Green or Italian Red etc.
3) Lack of widespread distribution.
I heard about good compliments to Pollyscale paints. But it is quite rare in my own country, and I heard it is expensive too. So Gunze acrylics is my favourite.
I am so satisfied with Gunze paints that it is exciting to watch the paint dry.
