Quote Originally Posted by pelerin
David,
Do you know why it is recommended to reverse the usual sequence (i.e., tone first) for selenium toning? I have tried both Vandyke and POP with selenium and toning first seems to work just fine. I wonder if there is a benefit to the different order or is it just following standard practice for bromide papers?
Celac.

Moderator's apology--Oh, crap! I accidentally pressed the "edit" button instead of the "reply" button, Celac, and I edited your post, deleting half of it I think, instead of responding to it. Sorry about that, and I hope the question and the answer are clear.
As far as I understand toning for albumen prints, the recommendation is to tone first before fixing. The traditional toners (gold-borax or gold-thiorea) basically leave the silver chloride undisturbed, while the high percentage of sodium thiosulfate in Kodak's Rapid Selenium Toner (about 30% as I recall) works to dissolve the silver compounds. Hence the very visible drop in density when the print is immersed in KRST prior to fixing. The fixer then removes the remaining non-image silver. So toning in KRST prior to fixing introduces two stages where hypo gets to work on the print.

I think that selenium toning after fixing gives more control over the final density and tonality of the image for two reasons: first, the overall image density is already established, and second, the dilution of the selenium toner, and the duration of immersion allows us to decide when the print "looks right." It's much harder to do this if selenium toning comes before fixing, since its difficult to visualize the full extent of the bleaching effect of hypo.