The first colour has been laid. Dollar store Neon yellow nail polish, thinned with Acetone.
Some more practice shots.
A little more consistent, should be much better with a straight needle, and the right thinning, and PSI, for now I have the MAC valve about half closed, and the comp at about 20PSI. The difficult part is the paint will surge a bit once I clear the tip. I clear it off on the masking template then move the brush into position as I depress the trigger. The new needle will allow a much smaller line, much closer to a pencile line, which is what I need. There is definately a technique to this small shading, keeping the tip and needle clean seem to be key. I have found I have to wipe the needle and tip after every row.
First pic is with Tamiya Acrylic, second is with Model Master Acrylic.