I've returned to modeling and have made some custom decals on clear inkjet decal paper purchased from Hobby Lobby. It's the same size as the old Testors paper they carried, 8.5x5.5. Once made I seal them with clear acrylic spray fixative. Its worked okay for some smaller decals like instrument panels and most recently I made black U.S. ARMY letters for under the wings of a B-24. They look pretty good on the neutral gray. I then tried to make the yellow serial numbers for the tail and large yellow numerals for the side. They look perfect on the decal sheet with the white background but once I put them on the olive upper surface of the model they basically disappear. They almost look opaque.
Question, am I doing something wrong, is the inkjet paper not correct for what I'm doing? If I use white paper I would have to trim the letter precisely and the numerals on the tail are about 2/16 high. Do I need to find a color laser printer instead, would that be a darker ink? I had to buy some Techmod yellow letter decals and they work great but I've planned to make some nose art with yellow in it for another project. Suggestions?