The 80 slide Kodak Carousel slide trays can take slides up to 3.2mm thick.
So this includes our plastic 1.8mm slide mounts and glass 3mm slide mounts, as well as other slide mounts such as old fashioned card mounts or ‘CS’ or ‘KLM’ thin plastic mounts.
However, the golden rule is not to mix slide mount types as the change in thickness will give focus shifts entailing either manually changing lens focus or autofocussing (if you have it). Either will be irritating to the audience and projectionist.
We recommend not using 140 slide magazines at all (if you can find them!), even if your projector can use them, as they can sometimes misfeed on occasions.