Julián, they are 1:1000 resin printed. They are printed before I upgraded the printer for anti-aliasing too. Anti-aliasing makes the screen the uv-light is projected through have gray tones and not just black or white. This makes "steps" in the model smoother.

Rob, I'm not sure. I searched the web for information on Spanish gun carriages and found that they were red at an earlier period and decided it was good enough for me. I have seen yellow, too.