I'm about to start a Revell B-25J, and am looking for a technique to do the various clear parts, which have recessed lines for the framework. I'll be using Testors spray for the body, so would like to find a thin olive drab marker to use.

Does anyone make a marker specifically for this task?

What do others use?

A search only found a company named MilSpray which produces markers for proto vehicles.

Most markers that I've seen have a fairly broad tip. For what you're intending to use one for, you'd need a fine tip. I did find a line of markers with a very fine tip in a local Art supply store, which since has long gone out of business. Your best bet would be to start your search with a chain store like Michaels. While they had a wide range of colors, they weren't geared to military colors. More like the color pallet of Crayola crayons.
Joel

Joel - I was actually asking here due to my disappointment with what I got in an art supply store on Monday. I had been told that Prismacolor had a light and dark olive drab, but it turned out to be light and dark olive green - neither of which is even close to the Testors spray color.

Most art markers these days have both a narrow and broad end on the same marker. My next plan is to take an example of the spray with me and try everything in the store that might be close. They provide pads for just this purpose.

A bunch of years ago Testors came out with a line of markers aimed at the model railroad market, including several colors for marking the sides of rails. I'm surprised that no-one has done that for the military modeling community.