[RA4] Portra B&W Paper
I have a box of Portra B&W paper designed to be developed in RA4 chemistry.
I'm not sure how old it is but the instructions inside say to treat it like Supra III paper so I suppose it's of that vintage. The Olympics 'worldwide sponsor' logo is on the box.
The paper was bought at Nova Darkroom from their bargain box quite a few years ago I think and it's sat unused in the darkroom until today. I didn't think it would give good results but I was really surprised to see a really nice image and bright white borders. I have some Supra Endura which is 18 months out of date and the borders are yellowing - not much but it's apparent when placed next to fresh MGIV for example.
So my question, is it just a fluke that this Portra paper has lasted better than newer paper or was it completely different beast compared to colour RA4?
More likely that it's a fluke the Super Endura is yellowing so early. It is supposed to be a super long lasting paper. But, as I understand it, the BW Portra was a completely different beast. Kodak only made it for a short time. I understand it had stability and fading problems. Dyes to produce black are much more difficult than color dyes.
Some b&w monochome RA-4 paper shifts to a black with magenta hue with time, so don't think it will last forever.
Mike, you mean the image on it won't last or the paper prior to exposure?
The paper shifts. Once exposed and processed the monochrome image is as stable any dye process. RA-4 bleach/blixes out most of the sliver as I understand it.
So stable in colour print terms, which I view as being shorter than traditional monochrome silver based prints properly washed.
If it mentions Supra III, then the paper you have is more than 10 years old. You are lucky to get any suitable result from it as the Supra family was not noted for good keeping. It turned yellow and lost speed. Endura has pretty much fixed that problem, but no true color paper can keep as well as a comparable B&W paper developed in a color process.
The B&W paper you have has only one emulsion, not 3 and it has fewer layers and different chemicals to form the dyes. So, it is easier to coat and easier to formulate such that it keeps better.
Good luck with it.
It's a nice paper and quite convenient when I've developed B&W negs but got RA4 chemistry in the Nova.