see also Applying Edge Dressing
Edge Dressing is a product designed to finish the edges of the soles of shoes and boots. Most often edge dressing is black, although brown is also common. Edge dressing is a thin liquid which is applied by either a built-in applicator sponge on the bottle, a cotton wool dauber, or a cloth.
Edge dressing stains very easily, so care should be taken to allow it to dry and to wipe off the soles of the boots after edge dressing is applied prior to the client getting up.