When a massage therapist or business refers to medical massage verses just massage therapy they are generally distinguishing between a deep tissue, injury treatment or sports massage verses a relaxation, swedish or spa massage. The intention of the massage is different.
Calico (in British usage since 1505[1]) is a plain-woven textile made from unbleached and often not fully processed cotton. It may contain unseparated husk parts, for example. The fabric is far less fine than muslin, but less coarse and thick than canvas or denim, but it is still very cheap owing to its unfinished and undyed appearance.
For washable items: Modacrylic fiber is a manufactured fiber in which the fiber forming substance is any long chain synthetic polymer composed of less than 85% but at least 35% by weight of acrylonitrile units. (-CH2CH[CN]-)x. A modacrylic is a synthetic copolymer. Modacrylic fiber is inherently flame resistant.