Microprinting is an anti-counterfeiting technique in which very small text is added to the artwork. The type is set so small that it is difficult or impossible to read with the naked eye. This also makes it difficult to reproduce accurately using copiers or scanners.
Typically the text is set to a size of 1pt (or smaller), using only upper case characters. By omitting all spaces the text looks even more like a solid line at a distance. Sometimes a single easily overlooked spelling error is inserted as an extra safety measure. Printing the text on a background makes it even more difficult to detect. Often the letters MP are printed somewhere on the document to indicate that it contains microprinting.
Microprint is used on currency, bank checks, vouchers, and other items of value. It is often combined with other safety techniques such as holograms, void pantographs, prismatic printing, hot stamp foil printing, infrared visible inks, or watermarks.