How do you develop photographs from antique glass slides?

Answer 1

You don't tell us whether your glass slides or plates are negatives or positives. You also don't tell us what size they are. If they're antique they're probably black and white, but they could also be an early color process or hand-tinted lantern slides. There are a lot of variables, so there are several possible approaches, depending …

If you do not have a photo darkroom or cannot rent one, you will have to seek out a professional photo lab which can still do these processes since the corner drugstore will have no means of handling glass plates of any description.

In the earliest days of negative-to-positive Photography, all printing was done by direct contact, negative on top of paper. This is one reason old glass negatives tend to be relatively large. If what you have are black and white glass negatives, they can be printed by contact on any black and white photographic paper in a photo darkroom using an enlarger as the light source. I would use an enlarger because it is easier to control since most papers remaining on the market are relatively high speed enlarging papers. I doubt there are any slow papers specifically made for contact printing manufactured any longer. You will need at least a heavy sheet of clear, good quality plate glass to set on top of the negative and paper in order to insure solid contact. If you have a contact printing frame with a spring back, that is even better. If the contact between negative and paper is not total, there will be areas of unsharpness. The paper is developed in the usual manner. Again, if you can't do this yourself, you'll need to find a professional lab with the equipment and expertise.

If they are negatives and you wish to enlarge them, the size of the original plate determines the size of the enlarger you must use. If they are 4x5-inches or so, then you must have access to a 4x5" enlarger, and you will have to cobble together some sort of holder for the glass plate that fits in the enlarger.

If the "antique glass slides" you have are in fact positives, sized about 3-1/4" x 4-1/4", they are probably lantern slides. I have little expertise in this area, but I would think you would have to have made what is called an internegative from the positive. Prints are then made from the internegative. I do not know of any direct positive (positive to positive) black and white paper, and if there was one it's surely not made now. There were direct positive color papers made for making prints directly from color slides without an internegative, and such a paper might work with a glass lantern slide, but you'd need a professional photo laboratory in any case unless you have access to a color lab.