I made these rough/smooth boards with balsa wood and sandpaper. The first has only two sections, sandpaper on one side and smooth wood on the other. The second has 5 alternating strips of sandpaper and smooth board. And the third has five gradations of coarse to fine sandpaper. They are the first introduction to tactile sense.
The next step is five pairs of boards with matching sandpaper from coarse to fine. The goal is to match the pairs through tactile sense alone. This means that I'll be introducing a blindfold with that activity. I need to finish the set though because I have only 4 of the 5 pairs made. I've been dragging my feet since DJ didn't seem to like the first lesson but now I think it's time to get moving.