Test for possible age-fogging in RA4 paper
I have been trying to recalibrate a Colorstar 3000 analyser and noticed that the unexposed part of the test strip used to calibrate neutral grey was, when processed, coming out an ivory/cream colour and not a pure white. While unexposed but fully processed Kodak Supra Endura may not be as white as say Ilford MG it looked quite ivory/cream.
I performed what I think is the right test tonight which was to remove a piece in the total darkness and process in Kodak dev, stop and blix, wash and dry. Then I removed a second piece and just blixed, washed and dry.
On examination there was a clear difference. The blixed only piece was a bright white whereas the fully processed piece was an ivory/cream colour
My understanding is that if there is no age-fogging both pieces should be the same colour. Is this correct?
If I have age-fogged paper to the extent described aove what effect would this have on a print from a neg other than white appearing ivory? I haven't got that far as I am still trying to calibrate for neutral grey.
Is the box a throw away item now?