Need suggestions as to what to use to separate the OD top color from the gray bottom. I use an airbrush for most of my painting. I don't want a tape line.

Darrell,

I would recommend using silly putty, check out the YouTube link below. I have tried many different masking methods, and so far one of my favorites is the Uhu Adhesive Putty. The putty is very malleable, relatively cheap, and has a low tack. The putty cleans up easily, and you can reuse it. There's a link below to the amazon page for the item. I use the Uhu putty in the same way the guy uses silly putty in the YouTube video, and for larger surfaces I use the putty in conjunction with masking tape.

This isn't the only way to mask off areas, and I encourage you to try several methods on a 'stunt' model to figure out which works best for you. Hope this helps.


https://youtu.be/GZhxSs70wgo

https://www.amazon.com/Adhesive-Removable-Reusable-Nontoxic-pieces/dp/B013FA72M0/ref=sr_1_1?ie=UTF8&qid=1520698533&sr=8-1&keywords=uhu+tac+removable+adhesive+putty