Paper towels, cloth, coins, written words on paper, the edge of a knife etc. I tried using slides too, but I don't remember being too successful. One thing to

Paper towels, cloth, coins, written words on paper, the edge of a knife etc. I tried using slides too, but I don't remember being too successful. One thing to note for whoever is interested: being pocket microscopes, you don't treat them as precision instruments. You (and your kids) drop them frequently. They are quite sturdy, but after countless drops the quality of the image starts to suffer.