Waterproof and breathable, they should also be rather tough, depending on the horses and their surrounding. The outer fabric determines a rug’s toughness, measured in Deniers. They indicate the weight in grams for a 9000m long thread.Rugs are padded on the 2/3rds of their height, the lower end being with nylon. There are different weights of padding. Note also that the weight of the padding is not the only determining element against the cold. The shape of the rug also plays an important role (belly flap, high neck), as well as the outer fabric.