John Mercer was a calico printer and chemist. Born on Feb. 21, 1791 in the parish of Great Harwood, England, he was the son of Robert Mercer, a hand loom weaver and farmer. Mercer's father died in 1800, so at the age of nine John became a bobbin winder and later, a hand loom weaver. In 1807 he became interested in dyeing and began learning the techniques. He entered into a partnership that lasted a little more than a year. In 1809, Mercer began an apprenticeship in a print works. By 1810, he had returned to hand loom weaving, inventing many ingenious designs. During this time, he studied mathematics and chemistry. In 1813, he resumed work as a dyer. From 1825 to 1848, Mercer was a partner in the firm, Fort Bros. During his career, Mercer developed a process known as Mercerizing, through which cotton fabrics become thicker and shorter. Mercer died in 1866, having been ill for two years.