Interface pressure mapping involves using sensors to quantify the pressure between two contacting objects, such as a person and their support surface. Pressure mapping systems can be made in many configurations for different uses but the most commonly encountered clinically are the thin mats used by seating specialists. These mats are approximately 18 inches by 18 inches and are composed of a matrix of small sensors and a cover. When a person sits on such a mat, the sensors read pressure at individual locations on the thigh or buttock. This data is transferred to a computer where it can be analyzed. Evenly distributed pressure is preferred.