Can anyone suggest the best type of cardboard used to mount color slides? The type Kodak used is not thick--about the thickness of regular chipboard--but much stiffer. I have a die cut for manufacturing my own Super Slide cardboard mounts on a letterpress. These are the 4x4 cm format mounts for 127 film or for cropping down 120 film to run alongside 35mm slides in a regular Carousel projector. I have a good adhesive system for mounting and already made some of these from regular chipboard. They work pretty good--but I'd like something stiffer. Gepe no longer makes glass Super Slide mounts and new old stock ones go for a fortune on ebay--so I really want to be able to make my own cardboard ones. Advice appreciated.