Where does everyone get the sheets that slide onto your bottom boards with the grid pattern used to count mites?
Most suppliers have them. Dadant, Mann Lake Ltd, Walter Kelly, Betterbee, Miller Bee supply, etc. Access their webs sites and search for mite board or some variation. I've goone to bottomless hives and have built in rails on which to slide the mite boards onto. I then make my mite boards out of 1/4 veneer and paint them white. A little coat of oil or gel and I can count mites. A slight adaptation will work on any SBB.