Rubylith

Rubylith is a brand of masking film, invented and trademarked by the Ulano Corporation. Today the brand has become genericized to the point that it has become synonymous with all coloured masking films.

Rubylith consists of two films sandwiched together. The bottom layer is a clear polyester backing sheet. The top layer is a translucent, red coloured, self adhesive emulsion. It is designed to be both easy to cut with a knife and light safe for use with orthochromatic films.

Rubylith is used in many areas of graphic design, typically to produce masks for various printing techniques. For example it is often used to mask off areas of a design when using a photoresist to produce printing plates for offset lithography or gravure. It is also frequently used during screen-printing.

Ulano also produces a yellow coloured, masking film called Amberlith, that is not light safe but easier to use for masking when not employing a photoresist.

The physical layouts of the first generations of Intel microprocessors (at least the Intel 4004, 4040, 8008, 8080, 8085, and 8086) were designed by physically cutting sheets of Rubylith into thin strips to lay out the circuits to be printed, a process made virtually obsolete by current computer graphic design capabilities.

See also

• Coordinatograph - a machine used to precisely cut rubylith

External links

• Official website