It’s important to use water-soluble glue as this gives you the opportunity to soak the specimen off the card if required.
It used to be simple to buy thin, clear water-soluble ‘school glue’ with brand names like Gloy or UHU. But these products have vanished for reasons unknown to me. So having reached a glue cross-roads in March 2010, I decided to get samples of some potential products and test them out.
Scotch Scrapbooker’s Glue. No ingredients on the packaging but looks similar to Gloy of old. The precision tip applicator could be really convenient but unfortunately the glue is far too thick for carding. So you need to squeeze a load out into a little pot, dilute with about 1 part glue to 1 part water and mix. A pity it has to be diluted but I recommend this.
PVA. Opaque white glue. This is pretty much the standard at OUMNH now. I tried out some of their glue and wasn’t impressed: too thin, dried too fast, and went through a nasty gummy phase before setting which quickly started gumming up my forceps, fingers and brush. It takes longer to soak beetles off that have been carded in PVA, and much longer to wash your carding brush.
Fish-glue. Took one whiff and abandoned any idea of using it!
Wallpaper Paste. I admit I only tried it once, years ago. It went mouldy really quickly so I’ve never bothered trying again.