Microprinting

Microprinting is the production of recognizable patterns or characters in a printed medium at a scale that typically requires magnification to read with the naked eye.

It occurred to Boni that if he could reduce rather than enlarge photographs, this technology might enable publication companies and libraries to access much greater quantities of data at a minimum cost of material and storage space.

Over the following decade, Boni worked to develop microprint, a micro-opaque process in which pages were photographed using 35mm microfilm and printed on cards using offset lithography.

[5] For example, on the series 2004 United States $20 bill, microprint is hidden within the border in the lower left corner of the obverse (front) side, as well as the Twenty USA background.

[7] Microprint of the smallest scale is only producible by hand using engraved offset printing plates or some other method of intaglio (printmaking).

While these printers make microprinting faster and easier to produce digitally, they still have not reached the true sub-pixel size of less than 1 point.

[12] Using gold nanoparticle inks on a glass substrate, scientists concluded that it was possible for them to control the production of print patterns to a scale of 2 microns.