List of duplicating processes
This is a partial list of text and image duplicating processes used in business and government from the Industrial Revolution forward. Some are mechanical and some are chemical. There is naturally some overlap with printing processes and photographic processes, but the challenge of precisely duplicating business letters, forms, contracts, and other paperwork prompted some unique solutions as well. There were many short-lived inventions along the way. Duplicating processes. "Within each type, the methods are arranged in very rough chronological order."