All paints can be airbrushed without thinning. All you need is enough pressure. If you want to be able to CONTROL what the spray does you will most likely need to thin most of them. I have had good luck airbrushing MM Acryl right from the bottle, depending on the bottle. If it’s new it works fine. If it’s been sitting around a few months and been opened and closed and opened and closed a few times it starts to thicken.
The bottom line is that there is NO single, cut-and-dried answer to the “How Much Do I Thin” question. The (admittedly ambiguous) answer is you thin as much as is necessary. IF the paint won’t spray properly AT THE PRESSURE THAT YOU WANT TO USE then it needs to be thinned. If it sprays at the pressure you want to use then it doesn’t need to be thinned. Since this question comes up about once a month I wrote a page about it on my web site. [url=]Here Is The Link[/url]