Jul 31 2010

Glossary of Terms for
Paper and Printing

"L"

LA21

Local Agenda 21. The global action plan agreed at the 1992 Earth Summit, which commits nations to sustainable development strategies. In the UK, local authorities have been tasked with co-ordinating LA21.

LABEL PAPERS

A large variety of various types of plain or coloured body papers which have been gummed or to which a self-adhesive material has been applied, and subsequently cut into a vast number of shapes and sizes depending on end use and surface application.

LAID FINISH

Laid finish papers feature a subtle linear pattern called "laid lines." These lines are created by a dandy roll with wires running parallel to its axis.

LAMINATION

The adhering of two or more vectors/substrates together. Usually a clear material applied to a printed surface. A range of hot and cold laminates are commercially available.

LAMINATION

The adhering of two or more vectors/substrates together. Usually a clear material applied to a printed surface. A range of hot and cold laminates are commercially available.

LASER COMPATIBLE

Papers engineered with special properties that assure smooth and consistent performance on laser equipment.

LASER CUTTING

Very fine cutting by laser, where traditional die-cutting cannot achieve the required level of detail.

LASER DIE-CUTTING

Technically not a die-cut, laser die-cutting is an extension of the photographic process. A metal template made from black-and-white artwork performs the role of a film negative. Wherever there is a hole in the template, a laser beam passes through and vaporizes the exposed area of the paper. Extremely precise, lasers enable the creation of amazingly intricate patterns with ease.

LASER PAPERS

Papers with special coatings or hard finishes that are optimised for laser printers and copiers.

LASER PRINTER

A print engine in which a laser is used to expose an image on a photoconductive drum or belt by discharging blank areas. The belt is then toned with a charged toner which is then transferred to the paper and fused there by heat and pressure.

LETTERPRESS

A relief printing method using cast metal type and raised images made on plates. Raised areas are inked and pressed against paper to transfer the text and images.

LIFE CYCLE ASSESSMENT/ANALYSIS (LCA)

A method of evaluating the environmental impact of a product 'from cradle to grave', including how it's made, how it's used and how it's disposed of.

LIGHT FAST / LIGHTFASTNESS

The ability of a print to withstand prolonged exposure to light with minimal or acceptable change.

LIGNIN

Non-cellulose material found in wood and other cellulose plants; lignin in paper makes it weaker and more inclined to discolour when exposed to light; in the chemical pulp-making process most of the lignin is removed. Lignin is present in mechanical pulp.

LIGNIN

A non cellulose material found in vegetable plants that may be considered as a binding agent or cement between the fibres of the plant. Any lignin left in the pulp can cause paper to age and yellow over time.

LIKE-SIDED

Paper that has the same appearance and characteristics on both sides.

LINED CHIPBOARD

Unlined chipboard that is modified by use of a thin layer of different pulp to provide a liner.

LINEN FINISH

A paper surface design made by embossing the paper with a linen cloth pattern.

LINEN FINISH

A finished paper that has an overall embossed pattern on the surface resembling the look and feel of linen cloth, and one manufactured with engraved embossing rolls.

LINES PER INCH (lpi)

The fineness of a halftone screen is measured by the number of lines per inch. The more lines per inch, the more detailed the printed image will be.

LIP

Lines Per Inch. A measure of screen frequency.

LITHO

Print process by which specific areas of a printing plate are chemically treated for the image areas to take ink and the non-image areas to take water. Capable of very fine detail and photographic-quality reproduction.

LITHO

Industry jargon for lithography or offset lithography.

LITHOGRAPHY

The process of printing that utilises flat inked surfaces to create the printed images. The most common printed method in use today, lithography is based on the principle that oil and water don\'t mix.

The image to be reproduced is created on a printing plate with greasy material that repels water. The plates are run wet so that oil-based inks adhere to the greasy parts of the plate, which are transferred to a blanket and pressed onto paper.

LOADING OR FILLER

Fine white pigr/m2ent in the form of powder or slurry used to improve smoothness, opacity, brightness and dimensional stability of paper and board.

LOW-GRADE WASTE PAPER

Commonly referred to as bulk grades, usually of lesser value, consists of newspaper, corrugated and mixed paper.