Glossary

IDLER ROLLERS
Any free turning roller/roll in a web press used to support and guide the web as it travels thru the press. Often times the roller has a rough or "grated" surface, to minimize tracking and smearing of freshly printed surfaces and to aid in gripping and guiding the web of paper.

ILLUMINATION
See standard illumination.

IMAGE DENSITY
A perception of the image darkness as detected by the eye or measured by a reflection densitometer; see reflectance.

IMPOSITION
Arrangements of pages on a sheet in such a way that when folded will fall into correct page sequence. The proper placing of pages on a layout for printing, such that the pages will appear in proper sequence in the signature after folding.

IMPRESSION
In printing, the point where ink is transferred to the paper. An impression is one complete revolution of the printing cylinder. The pressure (see back pressure) or the print left by the press plate or blanket when it comes into contact with the paper.

IMPRESSION CYLINDER
The cylinder against which impression is made: used to create the pressure required to transfer the image from the blanket (or plate) to the paper surface.

INDIRECT PRINTING
See offset.

INDUSTRIAL PAPERS
Broad term referring to papers manufactured for industrial uses such as packaging, card boards, tissues, toilet paper, and wrapping papers.

INFINITY SYMBOL
Symbol used to denote compliance of the ANSI spec for permanence of paper. These papers are alkaline (uncoated papers) that should last several hundred years without deterioration under normal use and storage conditions. (This specification is undergoing revision to include coated papers.)

INK FOUNTAIN
The reservoir from which ink is metered to the ink rollers on the printing press.

INK JET PRINTING
Also "jet" printing; pressureless and plateless forms of printing, generally where a variable image is generated from an electronic media or computer. The digitized information generating the image "triggers" the squirting or deflection of a very fluid liquid ink through one or more nozzles onto the paper surface: can be likened to graffiti spray can painting.

INK RECEPTIVITY
See K & N ink receptivity.

INK TRAPPING
See trapping.

INKOMETER
See tack.

INKS
See printing inks.

INTAGLIO PRINTING
See recessed printing.

INTEGRATED MILL
A mill manufacturing complex that produces paper from pulp manufactured at one site.

INTEGRITY
The quality of the paper surface finish.

INTERLEAVING
The placing of flat sheets together in proper order before binding.

INTERNAL BOND STRENGTH
See plybond.

INTERNAL SIZING
See sizing.

INTERNATIONAL ORGANIZATION FOR STANDARDS
See ISO.

INTERNATIONAL PAPER SIZES
The standard range of metric paper sizes (A, B and C) as defined by the International Standards Organization.

ISO
Abbreviation for "International Organization for Standards," which develops and publishes standards for a variety of technical applications, including paper (see MA), communications, printing, and data processing; also certifies quality control programs (ala ISO 9000).

I.G.T.
A laboratory printing device that uses special fluids or inks for assigning numerical values to the measurement of surface strength; see picking. The I.G.T. abbreviation is for the Amsterdam Holland manufacturer of the equipment: "Instituut voor Grafische Techniek."