@JJohnson59, thanks!
@Bkkinman, I overlap the putty but leave the edges sticking out from under the putty so the next color overlaps the edges of the previous color. Sometimes I do miss an edge here and there and have to do touchups.
I just did the NATO camo on this I Love Kit JLTV a couple days ago. Scroll to the bottom. The masking didn’t take as long as it did on the M113. I used the same putty technique on the JLTV to paint the NATO camo.