K - Abbreviation for black in four-color process printing. Hence the 'K' in CMYK.

Key - (1) The screw that controls ink flow from the ink fountain of a printing press. (2) To relate loose pieces of copy to their positions on a layout or mechanical using a system of numbers or letters. (3) Alternate term for the color black, as in 'key plate.'

Keylines - Lines on a mechanical or negative showing the exact size, shape and location of photographs or other graphic elements. Also called holding lines.

Key Negative or Plate - Negative or plate that prints the most detail, thus whose image guides the register of images from other plates. Also called key printer.

Kiss Die Cut - To die cut the top layer, but not the backing layer, of self-adhesive paper. Also called face cut.

Kiss Impression - Lightest possible impression that will transfer ink to a Substrate.

Kraft Paper - Strong paper used for wrapping and to make grocery bags and large envelopes.