Stan160
Member
An easy way to tell is to look at the back (emulsion) side. If its Kodachrome you'll be able to see a relief image as you tilt it to the light and get it just right. That is unique to Kodachrome.
Your slides may still be Kodachrome, but sheet film. It was available in 2 1/4 X 3 1/2" sheet film, among a bunch of other sheet sizes.
Finally had a chance to check the transparencies while visiting my parents at the weekend.
No relief image on the emulsion side, so not Kodachrome. No manufacturer's name or film type on the film borders so no idea what it is. I think this was 120 film as although each image is cut and individually mounted in card, the edges of some which are no longer attached to the mount aren't perfectly straight on the short side.
Ian