quick stick

the property of a pressure sensitive adhesive which allows it to adhere to a surface under very light pressure. It is determined by the ability of the adhesive to quickly wet the surface contacted. This term can also apply to water and heat sensitive adhesives.

quiet zone

a clear space, containing no dark marks, which precedes the start character of a symbol and follows the stop characters.

radio frequency

non-optical automatic identification devices that use radio waves to transmit data.

radio frequency tag

an electronic tag capable of receiving/storing and/or transmitting digital information.

range of a scanner

The larger the element, the greater the range and ease-of-use of a scanner.

rate of set

the time required for an adhesive under a specific set of conditions to arrive at a fiber tearing bond.

reactivation, heat

to restore the tackiness of the adhesive with heat and bond under pressure.

reactivation, solvent

to restore the surface tackiness in a dry adhesive film with a suitable solvent.

ream

500 sheets of paper.

ream marker

a piece of paper used to show divisions between reams.

ream weight

the amount which one ream of paper weighs.

reflectance

the ratio of the amount of light of a specified wavelength or series of wavelengths reflected from a test surface to the amount of light reflected from a barium oxide or magnesium oxide standard.

regenerated cellulose cellophane

a thin, flexible, transparent cellulose material made from wood pulp and used as a moistureproof wrapping.

register

the exact corresponding placement of successively printed images and/or successively die-cut labels.

relative humidity

the ratio of the amount of moisture contained in the atmosphere to the amount of moisture that can be carried in the atmosphere at a given temperature. Relative humidity is expressed in percent -- 75% RH That means at the temperature that the air is 75% saturated with moisture. Ideal conditions for many methods of printing are 75 degrees F and 50% RH Printers need special equipment to maintain this type of atmosphere year around. Most do not have the equipment and tend to run press rooms that are dry during the winter and more moist than ideal during the summer. The larger the deviation from ideal, the greater tendency will be for the sheets of paper to curl.

release

the act of freeing or separating a pressure sensitive adhesive from it's release liner.

release coat

the coating on a release liner that allows removal of the adhesive. It is frequently silicone based. See also liner and release level.

release coat transfer

the defect referring to the transfer of release coat from the release liner to the pressure sensitive adhesive. If excessive, adhesion will be reduced even when enough adhesive is applied to the construction. This is also called silicone transfer.

release level

a measurement of the force needed to remove a release liner from an adhesive. Testing is done on a standard size sample and force needed to separate the liner from the adhesive is measured in grams. The lower the number, the easier it is to remove the liner.

release liner

the component of the pressure sensitive label stock 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 its substrate.

remoistening

an adhesive system which is reactivated by application of water upon the adhesive film.

removability

a relative term applied to pressure sensitive adhesives to describe the force under which the adhesive can be separated from the substrate. A removable label would be one in which no damage or staining occurs to the substrate or the face stock on separation from substrate. This action is relative to substrate and application conditions. Few removable adhesives are removable from all surfaces.

removable adhesive

a pressure sensitive adhesive characterized by low ultimate adhesion to a wide variety of surfaces.

repositionable label

an application that requires that the label be initially removable, but build to permanence in a reasonable amount of time. Repositionable labels allow removal of crooked or wrinkled labels without destroying the substrate or label. By the time the label gets to the end user, it is a permanent label. Generally repositionable labels use acrylic permanent adhesives because they offer low initial tack, but build to permanent adhesion.

repositioning

a re-lamination of labels to a different position on the backing paper. While it is frequently done after die cutting, it can be done before. Separation of face and liner may temporarily reduce release values making the product easier to strip.

resolution

a term used to describe how finely detailed a printed image is. Usually it is used in relation to EDP printing. Related terms are DPI and dots per inch. The higher the DPI, the higher the resolution. Images look more natural at high resolutions. High resolution is also important for accuracy of bar code scanning. The narrowest element dimension which can be distinguished by a particular reading device or printed with a particular device or method.

rewinding

the operation of winding the paper from one roll to another. In printing this is frequently done for inspection purposes and to cut down larger diameter press rolls into lengths acceptable to the end customer. It is also used as a method of processing a second time rolls that did not wind evenly during initial production.

ribbon

a cloth or plastic tape coated with several layers of material, one of which is ink-like, that produces the visible marks on a substrate. Used on formed font impact, dot matrix, thermal transfer and hot stamp printers. Also called Foil.

Rockwell hardness

a common method of testing a plastics material for resistance to indentation in which a diamond or steel ball under pressure is used to pierce the test specimen. Die hardness is also measured on a Rockwell scale.

roll label

pressure sensitive labels that are stored in roll form.

rotary press

a printing press using plates formed to fit rolls and using paper in continuous rolls.

rotogravure printing

printing process that utilizes cylinders that have the design etched into the metal surface. the material to be printed comes in contact with the etched cylinder and the ink is transferred to the surface of the label material.

rubber based adhesives

adhesives composed of synthetic or natural rubber plus other components which form pressure sensitive compounds. Most rubber based adhesives offer fast quick stick and high ultimate adhesion. They do not age as well as acrylic adhesives.