Carbon paper

In 1801, Pellegrino Turri, an Italian inventor, invented carbon paper to provide the ink for his mechanical typing machine, one of the first typewriters.

[3] Carbon paper was the principal medium of reproduction for samizdat, a publication method used in the former Soviet Union in order to publish books without having to use state-controlled printing houses and risk the censorship or imprisonment.

Examples of these are receipts at point of sale (though they have mostly been relegated to being backups for when electronic POS devices fail) or for on-the-spot fine notices, duplicate checks, and some money orders (though the United States Postal Service has recently[when?]

converted to an electronic format), and tracking slips for various expedited mail services requiring multiple copies.

[7] Carbon paper disks are still used in school physics labs as part of experiments on projectile motion and position.