Stiff bristle - Suitable for midsoles, leather, rubber, plastics, some mesh and canvas.
Soft bristle - Suitable for all materials. Best used on suede, painted leather and mesh.
Nylon - Suitable for most materials such as, leather, canvas, rubber, plastic, suede, satin. Do not use on silk.
Steel - Suitable for undersoles only (do not use on painted areas or soft material).
Before using brushes test on small area. Always start off applying little pressure.