The electrically heated mat, covered with an aluminium sheet, can be placed on any work-table. The suction tube is connected to the latex sheet, or membrane, which lies over the picture. For cooling, the mat is simply withdrawn. For rapid cooling the aluminium sheet may be raised from the table by inserting two lengths of wood under it and turning them. A large picture may be treated by moving the mat to adjoining areas in turn. The total cost is about pound sterling 80. -- AATA