A painted edge fails in one of two ways: it chips at the corners, or it browns at the seam. Both happen because the paint shrinks differently from the leather as the bag dries out over the years.
Three coats — base, body, finish — distribute that shrinkage. One coat hides nothing. Two coats hide everything for the first season. Three coats hold for the lifetime of the bag, if the painter has the patience.
Most factories do one. Some do two. We do three, and we won’t drop it.