Fellas,
I know Vallejo has a line of pre-thinned acrylics and from what I have heard they are pretty fantastic. If only they were not so hard to get a hold of… The question is: Why don’t Tamiya, Testors, or Gunze have their own? I would pay extra. I take more time thinning my paint than I do cleaning the airbrush.
There is Model Master Acryl which is supposed to be thin enough to airbrush, but it goes on bumpy. I stick as much Tamiya thinner as I can fit in those jars when they’re new, and I sometimes still add more thinner once it’s in the airbrush.
You don’t really have to be spending time thinning. However much unthinned paint you put in, put in a “good bit less” thinner & slosh it around with the pipette or eyedropper. It’s not critical enough to have to be done so carefully.