In my search for better papers for Pd/Pt printing I also tried fumed alumia dry or wet applied. It gave better contrast and Dmax with several papers but bad mids and highlights (like too much restrainer). The fumed alumina suspended quite easily in Ethanol and that suspension has to be diluted with a lot of water (otherwise it soaks completely through the paper).
I am not so sure that more sensitizer increases Dmax. I investigated some prints under a stereo microscope and found often only the very top fibers get coated but in the mids it is apparent that some fibers get no or only very little Metal deposited. This explains the mottled mid tones. Papers like Buxton or Herschel have not that effect. I also investigated coated but not developed paper and found that different fibers within the paper surface have absorbed different amount of sensitizer. I have to make more of these studies but I think the goal is to get all the fibers absorb the sensitizer. Simply adding more will likely only act as a filter during exposure without contributing to image density.
Last edited by jakobb; 04-09-2013 at 05:25 PM. Click to view previous post history.