Lithography was introduced at the Kinngait Studios in the early 1970s. Unlike stonecut and etching, hand lithography requires no cutting of the printing surface. Instead, the design is simply drawn on a limestone block or aluminum plate with grease pencils or with a greasy liquid. The stone or plate is then inked with a grease-based ink while being continuously sponged with a thin film of water. The water repels the greasy ink, confining it to the area defined by the original drawing. Multi-colour prints usually require a separate stone or plate for each colour. In printing, the inked stone or plate, paper and tympan (protective covering) is cranked by hand through a press. Under tremendous pressure, the drawn image transfers to the paper. In recent years, several lithographs have included the application of chine collé. This technique involves pressing a thin sheet of sized, oriental paper to a heavier backing sheet and printing both at the same time, adding another dimension of colour and texture to the final image.