Live sole or false sole What’s the difference, and why does it matter? The sole is the weight-sharing surface between wall and frog, made from keratin, very similar to the wall. A healthy sole builds a thick protective callus. We protect that callus rather than thin it. Live sole Firm with a slight waxy sheen. Blends smoothly into frog and bars. False or retained sole Dead material that has not shed yet. Looks chalky or crumbly in wet climates. In dry it may flake in sheets or lift at the edges,