mould was such that the process of taking the type out disturbed the casting, causing variants and anomalies, and that the punch-matrix system came into use possibly around the 1470s. This raises the possibility that the development of movable type in the West may have been progressive rather than a single innovation. Gutenberg's movable-type printing system spread rapidly across Europe, from the single Mainz printing press in 1457 to 110 presses by 1480, with 50 of them in Italy. Venice quickly became the centre of typographic and printing activity. Significant contributions came from Nicolas Jenson, Francesco Griffo, Aldus Manutius, and other printers of late 15th-century Europe. Gutenberg's movable type printing system offered a number of advantages over previous movable type techniques. The lead-antimony-tin alloy used by Gutenberg had half the melting temperature of bronze, making it easier to cast the type and aided the use of reusable metal matrix moulds instead of the expendable sand and clay moulds. The use of antimony alloy increased hardness of the type compared to lead and tin for improved durability of the type. The reusable metal matrix allowed a single experienced worker to produce 4,000 to 5,000 individual types a day, while Wang Chen had artisans working 2 years to make 60,000 wooden types. Type-founding Stages Type-founding as practised in Europe and the West consists of three stages: Punchcutting If the glyph design includes enclosed spaces (counters) then a counterpunch is made. The counter shapes are transferred in relief (cameo) onto the end of a rectangular bar of mild steel using a specialized engraving tool called a graver. The finished counterpunch is hardened by heating and quenching (tempering), or exposure to a cyanide solution (case hardening). The counterpunch is then struck against the end of a similar rectangular steel bar—the letterpunch—to impress the counter shapes as recessed spaces (intaglio). The outer profile of the glyph is completed by scraping away with a graver the material outside the counter spaces, leaving only the stroke or lines of the glyph. Progress toward the finished design is checked by successive smoke proofs; temporary prints made from a thin coating of carbon deposited on the punch surface by a candle flame. The finished letter punch is finally hardened to withstand the rigours of reproduction by striking. One counterpunch and one letterpunch are produced for every letter or glyph making up a complete font. Matrix The letterpunch is used