Thanks for the information Maris. I've seen some good results of ortho materials shot though orange and red filters. I'm very curious as to what different color filters will do. I know a few collodion photographers who shoot through blue filters. Collodion is orthochromatic as well and in these cases shooting though blue filters makes for shorter exposure times and seems to improve overall contrast since it makes all of the light hitting the emulsion blue and the emulsion reacts more evenly across the image as opposed to shooting filterless. I haven't heard much about anyone trying this with the DP paper. In the end, this will probably come down to me experimenting with it but so many people here have great insight that I know will help move along the progress.