 Between 1436 and 1450 he developed hardware and techniques for casting letters from matrices using a device called the hand mould.Gutenberg's key invention and contribution to movable-type printing in Europe, the hand mould, was the first practical means of making cheap copies of letterpunches in the vast quantities needed to print complete books, making the movable-type printing process a viable enterprise.Before Gutenberg, scribes copied books by hand on scrolls and paper, or print-makers printed texts from hand-carved wooden blocks.