Glossary

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RATE OF SET

The time required for an adhesive, under a specific set of conditions, to arrive at a fibre tearing bond. Refer NS & LM.

REACTIVE DILUENT

A liquid used to reduce the viscosity or tack of an ink. The diluent becomes an integral part of the polymer which forms when the ink is cured.

READ AREA

A term used to refer to the scan path or scan area of a bar code.

REAM

Five hundred sheets of paper.

REAM WEIGHT

The amount which one ream of paper weighs. eg. 80gsm = 80 grams per square meter x 4 (number of sheets per square) = 125 square meters x 80 grams = 10,000 grams = 10 kilos for that ream. Refer LM.

RECYCLE

Process that describes reuse of a product.

REDUCERS

In printing inks, varnishes, solvents, oily or greasy compounds used to reduce the body and/or viscosity for printing.

RE/EPS - See POLYSTYRENE

REEL

A finished roll of Labelstock. A finished roll of labels. (Which is it to be???)

REFLECTANCE

The amount of light returned from an illuminated surface.

REFLECTIVE ART

Art which must be photographed by the light reflected from its surface. As apposed to non-reflective art.

REGISTER

The corresponding placement of one colour to the next, etc., as well as the printing placement as it relates to die cutting, scoring, perforating, etc.

REGISTER MARKS

Symbols attached to the original copy prior to photography, used for positioning films in register, or registering two or more colours when printing. In some cases, the register marks are produced on the cutting die as well as the plates.

RELATIVE HUMIDITY

The amount of water vapour present in the atmosphere, expressed as a percentage of maximum that could be present at the same room temperature. Relative humidity affects sheeted labels converted off the press from rolls of Labelstock for use in Laser and Ink-Jet printers. Refer NS & LM.

RELEASE

The force required to free or separate a pressure sensitive label from its release liner, using a specific measuring device. Refer NS & LM.

RELEASE AGENT

Materials used to facilitate the removal of moulded items from their moulds. These agents can cause serious problems in adhesion when applying labels to the moulded products.

RELEASE COAT

The release liner treatment material that allows pressure sensitive labels to release from the release liner. Usually made from silicone sprayed onto the release liner at about 2 grams per square meter. Refer NS & LM.

RELEASE COAT TRANSFER

The transfer of release coat from the release liner to the pressure sensitive adhesive during release.

RELEASE LINER

The component of the pressure sensitive labelstock which functions as a carrier for the pressure sensitive label. Prior to application, it protects the adhesive, and readily separates from the label immediately before the label is applied to product. Refer NS & LM.

RELIEF ANGLE

The angle of the raised portion of a printing plate.

REMOVABILITY

A relative term applied to pressure sensitive labels to describe the force or condition under which they can be removed from a substrate. A removable label would be one in which no damage or staining occurs to the substrate or the face material on removal. Refer AS & LM.

REMOVABLE ADHESIVE

A pressure sensitive adhesive characterised by low ultimate adhesion and clean removability from a wide variety of surfaces. Refer AS & LM.

RENDERING

The finished production of a design, drawing, painting, etc., by hand using any of various artists tools, ie. pencils, pens, knives, brushes or air brushes.

REPEAT

The printing length of a plate cylinder, determined by one revolution of the plate-cylinder gear.

REPOSITIONAL

The ability of a pressure sensitive label to be bonded to a surface, removed and repositioned. This can only be done for a limited period of time (20 minutes). Beyond that time, the bond may begin to become permanent, expect in cases where a removable adhesive is used.

REPOSITIONAL ADHESIVE

A permanent adhesive that can be removed and repositioned for a short, finite, time after application.

REPOSITIONING

The relamination of labels to a different location on the backing sheet following diecutting.

RESIDUE

Something that remains after a part is removed, such as removing a label and leaving adhesive on the surface.

RESISTIVITY

The ability of a material to resist passage of electrical current either through its bulk or on a surface. The resistivity unit of volume is the ohm-cm.

RETARDERS

Combination of liquids, solvents and extenders that are added to an adhesive, coating or ink to slow down the drying rate of the material. Refer IM.

REVERSE ANGLE DOCTOR BLADE - See DOCTOR BLADE

REVERSE PRINTING

Printing on the underside of a transparent film. Also a design in which the copy is ‘dropped-out’ and the background is printed making the copy appear in the colour of the background.

REVERSE ROLLER COATING

The coating is pre-metered between two rollers, then wiped off onto the web, which is driven by a third back-up roller. The amount of coating is controlled by the gap between the metering and applicator rollers and also by relative speed or rotation between the same two rollers.

REWIND (SHAFT) - or TO REWIND

The take-up spindle or mandrel on a press. Also the act of winding a roll of material through a machine to effect the opposite unwind.

REWINDING AND INSPECTION

The operation of winding the material from a press roll onto a core (or coreless) to produce rolls of the desired width, diameter and tension. Out-of-specification or damaged labels can be removed and replaced during this operation. Slices and/or joins are also made during this operation.

RIGHT READING

An image whose parts are spatially oriented to each other as they are on the original or as they are to be printed, in contrast to the way they would appear reflected in a mirror.

ROCKWELL HARDNESS

A method of determining the surface hardness of a substance. Degree of hardness. Also called ‘Shore’.

ROLLER COATER

A machine utilising rollers to mechanically apply an adhesive or coating to flexible substrates.

ROLL LABEL

Pressure sensitive labels that are produced in a continuous roll form.

ROLL-TO-ROLL or REEL-TO-REEL

A method of running material through a printing machine. A roll of material is fed into a printing unit, is printed, die cut etc., then is rewound into a roll as it exits the machine.

ROLL-TO-SHEET

A method of running material through a printing machine. A roll of material is fed into a printing unit, is printed, die cut etc., then is sheeted as it exits the printing machine.

ROTARY PRESS

A press that in normal use features a roll-to-roll (reel-to-reel) operation.

ROTARY PRINTING

Accomplished by means of a cylindrical impression cylinder and a cylindrical printing plate.

ROTOGRAVURE PRINTING - GRAVURE

Printing process that utilises cylinders that have the design etched into the metal surface. The material to be printed comes in contact with the etched cylinder (which is carrying the ink) and the ink is transferred. A rubber pressure roller facilitates this transfer. Also known as Gravure printing.

ROUGH SKETCH - Also called THUMB NAIL SKETCH

An impromptu drawing of a picture or design to present a concept, often in colour. Often developed into comprehensive artwork for reproduction. Note that copyright is automatic for sketches and artwork.

RUB TEST

Test performed to determine the durability and abrasion resistance of the printed surface of a label. Refer NS, LM & IM. Also refer to PAGE>>> for the Sutherland Rub Tester and a description of the equipment as recommended by the Winemakers’ Federation of Australia, and contained in the Australian Standard.

RUBBER BASE ADHESIVE

Pressure sensitive adhesive based on natural or synthetic rubber. Can be coated as a solvent, hot melt or emulsion system. Refer LM.

RUNNING REGISTER

That control on a flexographic press which accurately positions, while in the run mode, the printing of each colour station in the direction of the web travel. Also called circumferential register or longitudinal register.

RUPTURE

A cleavage or break in the adhesive film, resulting from physical stress.