a) Different shapes in wood. b) Made with flexible steel. c) Made of steel, d) Flexible rubber for transfers. e) Serrated flexible steel scraper
Kidneys were originally made of rubber in the shape of a kidney; now there is a large selection of shapes, that vary in degrees of hardness and pliability and are made of materials, such as plastic, steel, etc. They are used on thrown and hand-built work for shaping, cleaning and smoothing surfaces, also for pressing clay into and onto a mold and special ones are made for flattening out transfers.