I've got quite a collection of boxes of plates. Kodak, Ilford, Gervart and a few others.
They are mostly just collectable curios as they are usually all fogged beyond being useable, but I have tried quite a few and sometrimes find the slower ones (things below 50 ISO) ok.
I once tried some 'Wellington' plates which I think must have been circa 1920 and they weren't too foggy at all. Very sharp and contrasty, too. But I reckon they were only about 1/2 ISO, which is probably why they didn't fog.
Many are packed in pairs, always emulsion side facing each other, but quite a few are packed in fours. Here the emulsion always faces in towards the centre, but you have to be careful not to get confused as you remove the plates from the packing in the dark. From my 1920s Wellington plates to some 1970s Ilford and the Kodak and Gervart, too, this seems to have been the rule for several countries for over 50 years. The Agfa plates mentioned higher up the thread are the only exception I've ever heard of...
I have looked at a few orthochromatic plates under red light and really can't tell the difference between front and back. I would guess the front is creamy white and the back of a 'backed' plate would probably be red, but under red light everything is red! If it is unbacked and orthochromatic or ordinary then it is obviously easy, as the glass back is shiny and the emulsion is matt.
For pan plates with the sticky finger test, it only works on unbacked plates or plates where the backing is behind the emulsion, rather than on the other side of the glass. I have used plates with the anti halation layer under the emulsion and a 'clean' glass back, but since my darkroom isn't completely 100% light proof I use a changing bag, so can't get to lick my fingers to try to tell the emulsion side by stickiness! I have been told you can tell the emulsion side by smell, too. I've certainly experienced this with some matt printing papers that seemed identical on both sides, but again another limitation of using a changing bag, I can't get my nose in there...
I reckon knowing how the plates are packed is the only reliable way...
Last edited by steven_e007; 08-06-2007 at 05:38 PM. Click to view previous post history.