What makes boots waterproof? It's one of the more confusing labels in the footwear industry! Rubber boots are impenetrable and the best choice for standing water. Waterproof membranes create an inner bootie that keeps moisture away from the inner boot. Seam sealed waterproof boots are made of a leather upper which is heat sealed to create a waterproof barrier. Waterproof membranes and seam sealed waterproof snow boots work well in slushy snow or quickly stepping in and out of puddles.