Label Glossary & Terminology

To stick or hold, this occurs when two surfaces are stuck together by adhesion or an adhesive.

A measure of force required to remove an adhesive coated material from another surface under a specified angle and speed conditions, such as FINAT Test Method FTM 1.

A measure of the time which is needed to slide a specific area of a pressure-sensitive label from a standard flat surface in a direction parallel to that surface.

A substance capable of holding or bonding materials together by surface attachment or adhesion.

These are thermoplastic materials with 100% solids that are heated to temperatures above their melting point and applied to substrates in the molten state. 

These adhesives have had a dominant place in the label industry for many years and are used in wet-glue, self-adhesive and gummed paper formulations.

A pressure-sensitive adhesive with a low ultimate adhesion to a wide range of surfaces. It can be peeled-off or removed from most surfaces easily and should not leave a residue. 

These adhesives usually stick quickly to the surface they are being applied to and, after the normal bedding down period, their performance increases to form a fibre-tearing bond. They are designed to adhere at ambient temperatures. These adhesives usually cannot be removed intact or only with enough force to overcome the adhesive bond - in which case the label may be damaged. 

These can be permanent, semi-permanent or removable and are used specifically with synthetic film labelstocks.

These are designed to stick onto frozen meat packs with a labelling temperature down to -30°C and ultimate adhesion tolerances down to 50°C.

These adhesives remain removable and repositionable for some time after application before becoming fully permanent. These are often used where the pack to be labelled is not a constant shape and an operator needs to reposition labels that may have been applied off-centre. 

These are high tack permanent adhesives designed to wash off in various environments. For example, our PurityWash adhesives which enables labels to wash off glass, PP, PE, HDPE and PET bottles and containers during industrial cleaning processes.

This adhesive provides a low ultimate adhesion to a range of surfaces which can generally be removed or peeled-off intact.

The temperature of the surface to be labelled and the self-adhesive labels at the time of application. All adhesives have recommended minimum application temperatures, which are ascertained by means of tests, carried out in ideal conditions (i.e. smooth, clean, dry surfaces etc.).

A table-top, stand-alone or in-line device/machine which is used to automatically apply pressure-sensitive labels from a roll of labels onto a container or product.

Refers to the carrier sheet or web of a material used in pressure-sensitive lamination that carries the permanently tacky adhesive coated face material. This usually has a release (silicone) coating applied to it so that the adhesive will not stick too tightly to it.

Also referred to as the release liner, this is the component of the label laminate that protects the pressure-sensitive adhesive during manufacture, converting, printing and up to the final point of application. The backing is peeled away from the adhesive immediately prior to its application to a container, product or surface.

A standard method of identifying the manufacturer and product category of a particular item. 

A device used to identify and read a bar code.

A coating applied to a material to prevent absorption or interaction between the material and any subsequent coating. 

Label face and liner (polypropylene) film materials, which have been mechanically stretched (orientated) in both the machine and transverse directions during the manufacturing process.

The ability of a material, such as paper or plastic film, pressure-sensitive label stock or printed labels, to break down or decompose under natural conditions or processes. 

Sometimes used to refer to the siliconised liner material or liner layer of pressure-sensitive labels. 

Transparent cellulose film material is manufactured by chemically regenerating a dissolved cellulosic compound into a continuous thin web. Uncoated cellophane only has a few packaging uses, such as decorative wraps.  

Fibrous substance of wood, cotton or other vegetable matter.

High-frequency corona treatment has been widely accepted as a process for improving the adhesion of printing inks, lacquers, adhesives and other coatings onto plastic films, paper and metal foil, providing good results, and controllability and easy handling.

Perforations across the width of a continuous web for easy separation of individual sheets and/or fan folding of continuous labels. 

The process of changing the structure and properties of an adhesive, silicone, coating or ink by chemical reaction. This change may be effected by cross-linking or polymerisation initiated by catalysts, thermal treatment or by UV or EB radiation.

The tendency of a paper, either by itself or in a laminate construction, to bend or partly wrap around the axis of one of its directions. This is frequently caused by humidity changes or improper tension control. It may sometimes be defeated by using a de-curling bar set-up on the paper unwind of a machine.

Variation in the size of labels between the edge of the label and the edge of the printed image on the label.

Capable of being broken down (degraded) into natural elements or simpler compounds under normal environmental conditions. In the label industry it is a term most commonly used in relation to papers, laminates or films which will degrade or biodegrade.

The splitting of material into layers in a direction approximately parallel to the surface, e.g. the separation of self-adhesive print carrier from its release liner (silicone backing paper) in the printing machine.

A type of pressure-sensitive label that, once removed from the release liner and bonded to the intended surface, cannot be removed without damage, so that any attempt to remove is readily evident. This can also be referred to as a tamper-evident or security label.

The process of cutting a label shape with a die. Most self-adhesive labels and some wet-glue and in-mould labels have to be die-cut to shape as part of their manufacturing and finishing procedure. Depending on the type of label and the printing and/or die cutting requirement, the operation may be performed using high or hollow dies, flat dies, rotary dies or, most recently, with digital die-cutting.

A process involving the creation, storage, transfer and reproduction of printed images in a digital format so as to allow fixed or completely variable information to be printed on a label without printing plates. 

Labels that allow a direct thermal printer to create an image by applying heat directly to a label material which has a heat-activatable coating. No ribbon is required in the printing.

An electronic printing process in which a special heat-sensitive surface coated material is turned selectively black by the direct application of heat through the contact apertures of an electronically-controlled thermal print head. Read more.

The moisture content of a paper that has reached a balance with the atmosphere surrounding it, i.e. in a condition in which it will neither give up nor absorb moisture.

A method of coating a web of paper with resins, plastics or similar hot-melt compounds. The coating is applied through an extruded die positioned immediately above the nip between a supporting roll and a chin roll.

Any pressure-sensitive label in which the face material has been cut to the liner. A die-cut label product from which the waste matrix around the labels has not been removed. 

Any paper, film, foil, synthetic or other material that can be converted into labels. 

Labels manufactured from a continuous web of label stock and then folded into a zig-zag accordion style format for packing flat in boxes. The fold is created by horizontal perforations in the release liner. 

A transparent or opaque polymer material used as a face material or release liner for pressure-sensitive labels, or for the manufacture of shrink and stretch labels, in-mold labels, wrap-around labels or cut-and-stack film labels.

Flexible packaging accounts for more than 35 percent of all plastic packaging sales and has been growing rapidly in recent years, particularly replacing other forms of packaging - such as rigid plastics containers or corrugated materials. 

Flexography is a rotary relief printing process in which ink is applied to the raised surface of an image on a flexible printing plate, and from there, to the surface of a label or flexible packaging substrate. 

A foil (usually gold, silver or silver aluminium foil which has been covered) which has been laminated to paper, board or plastic film to produce a label or flexible packaging substrate. 

A label and/or adhesive that is in direct contact with food.

An adhesive which is designed to give good adhesion of a self-adhesive label on a cold or frozen substrate. An adhesive which can be applied at, and function at, temperatures below freezing point. 

Special inks that change colour or are removed when water or chemicals are applied. Mainly used for fraud protection applications. 

A supercalendered, smooth, dense, transparent or translucent paper manufactured primarily from chemical wood pulps, which has been well beaten during pulp preparation to secure a high degree of hydration of the stock, which gives glassine its transparency but also makes it more susceptible to atmospheric changes. Due to its curl limitations, its commonly used as a backing paper/release liner for pressure-sensitive roll-label laminates.

This is the characteristic of a surface which causes it to reflect light at a given angle. This relates to gloss label papers, gloss inks, gloss varnishing etc. 

This term is used in the metric system to denote the weight of paper or board; the measurement used is the weight of a single sheet of one square meter, expressed as grams per square meter. 

Grams per square meter. A method of measuring or indicating the substance of a paper or film substrate and adhesive or silicone coat weight on the basis of its weight, expressed internationally as grams per square meter. 

High density polyethylene. 

A coating of adhesive which is dry to the touch until activated by the application of heat through the thickness of the coated substrate. All heat activated labels require the correctly heated platen, the label and the labelling surface to be in contact under pressure, at application. Variations of heat, pressure and dwell time affect adhesion performance and have to be co-ordinated. 

The ability of a material to inhibit or withstand elevated and high temperatures without undergoing any physical or chemical changes.

The bonding together of two or more surfaces using heat, usually for sealing paper or plastics. 

A microscopically fine diffractive structure by which three-dimensional images are generated. Holograms provide powerful visual appeal as well as prestige and anti-counterfeiting / brand protection properties. 

A solid synthetic rubber-based adhesive supplied in dry form whose components melt and mix by the application of heat between 130 - 160 degrees. It dries at room temperature to leave a tacky pressure-sensitive surface. Hot-melt adhesives are used for many adhesive applications where their immediate speed of setting/bonding is ideal for fast production. 

The printing of changeable or variable copy onto blank or pre-printed labels, tickets or tags using a secondary printing device such as a computer printer, dot-matrix printer etc.

The name given to commercial and industrial digital offset presses manufactured by HP Indigo.

Labels which are required to withstand a range of conditions and extremes of climates which may include oil, water, chemical or grease resistance, high or low temperatures, abrasion or scuffing.

A test for release performance run immediately after coating and laminating of pressure-sensitive label stock.

The degree of stickiness or grab of an adhesive label surface when it is first applied to a product or surface. 

A printing press which is coupled to or incorporates other operations in-line and driven by the same drive shaft, or an electronic drive shaft in the case of a servo-driven press.

A label may be a piece of paper, paperboard, laminate, metallic foil, plastic film, fabric or synthetic material that can be affixed to almost anything to indicate its contents, nature, direction, ownership or destination. Labelling is the art of applying or attaching the label to a particular surface, item or product.

A machine that dispenses a self-adhesive label and applies it to a container, pack or product. The machine incorporates a means of removing the backing material (release liner) by pulling it over an acute metal beak, so leaving the label free to be applied to the product.

The cutting out of a label through the use of a computer-controlled laser. The laser cutter uses programs developed from the step-and-repeat function of label origination to guide the cutting head around each separate label profile. The laser cuts through the face material, either paper or filmic, and stops at the adhesive layer. 

Component of pressure-sensitive label stock which functions as a carrier for the label. Prior to label application, it protects the adhesive and readily separates from the label at the time of application.

Plastic film or paper materials that have been coated on one side with a very thin layer of metal, usually aluminium. 

Material or label substrate that is impervious to moisture or water vapour. 

Material which resists the uptake of passage of moisture. The moisture resistance of paper labels can be improved by varnishing or over laminating. 

Printing presses in which the web width may be as narrow as 150mm (6 inches) and range up to as high as 500m (20 inches), 600mm (24 inches) or even 700mm (28 inches), according to which press manufacturer is consulted.

Material that is not used when a roll or sheet of paper, film or labels is trimmed to the correct size or width. Trim width that is not utilised but usually calculated within the costs.

The unwanted transfer of an ink or varnish from one printed surface to another. The transfer of ink before it is fully dry from the face of one sheet to the back of the sheet above in the delivery stack of sheet-fed press, or from the printed surface to the backing liner in a roll. 

The application of a clear self-adhesive film to a label stock to provide increased protection or to enhance the image or quality of the label. Over lamination is usually carried out as an in-line process on narrow-web presses, or a separate operation for sheet-printed products. Heat-seal over-laminating materials are also available, although these are not normally used in label applications. 

The printing of additional images or text onto a pre-printed label, either over an existing image or within a space left during an earlier printing operation. The material being printed may be fixed or variable information. 

The process in which an ink, coating, adhesive or other material takes in oxygen to form an oxide. Traditional, non UV-curable letterpress and lithographic inks dry by the oxidation process. Adhesive films may deteriorate due to atmospheric exposure. Hot-melt adhesives may break down due to prolonged heating and oxide formation. 

Where an adhesive is laid down in strips parallel to the machine direction across the width of a pressure-sensitive label stock during manufacture. This is also called strip coating.

The force required to remove a pressure-sensitive label or tape from a standard test panel at a specified angle (usually 180 or 90 degrees) and speed after it has been applied to the test panel under specified conditions for a specific time. 

A peeler plate or beak is a sharp-edged, flat piece of metal around which the release liner backing material is drawn in a label applicator or dispensing system so that the label is carried forward from the backing and can be applied to the product or pack. 

An adhesive which, when applied to the specified surface, will display strong final adhesion and a permanent key within a short period of time. Generally difficult to remove without damaging the label or sticker. The actual strength of adhesion will depend on the nature of the substrate and the conditions under which the self-adhesive product is applied, consequently adhesion will build up over 24 hours and assessment of the effectiveness of a bond can show a marked difference with the passage of time.

The property of a material that allows or resists a substance to pass or flow through it.

Polyethylene Terephthalate. A clear, tough, solvent resistant material used for some label face materials and for the manufacture of mineral water, soft drinks and fruit juice bottles, and for some laundry detergent and kitchen bottles.

The image carrier in letterpress, flexographic and offset printing presses.

The cylinder in a printing unit to which the printing plate(s) or a plate sleeve is attached. Printer cylinders may have the shaft as a permanent part of the cylinder body, or have a removable shaft.

A long-chain molecular structure formed by the reaction and linking together of monomers. 

The technical machine design of a narrow web press today can be drawn on and incorporate a number of key areas into the building of a sophisticated press for high quality printing and converting. Such as, drives, whether conventional, hybrid/combined or single drive.

Pressure-sensitive adhesives differ from other types of adhesives in that they are able to form a bond at any time, are permanently tacky, are capable of bonding to any surface and are adhesive above their glass transition temperature. No activation by water, solvent or heat is required to exert a strong adhesive bond on materials as diverse as paper, plastic, glass, wood, cement and metals. 

Printability is the characteristic or ability of a label face material to permit high quality printed results. Although difficult to define precisely, good printability provides a uniformity of printed colour, uniformity of ink transfer, good quality of black-on-white image and consistency of ink drying and setting.

A coating that is applied to the surface of a label to protect the print and/or label stock from abrasion, chemicals, moisture or sunlight, or any combination of these.

Materials that are able to be reprocessed and used again.

The action of separating, processing and selling products manufactured from those waste materials that can be reprocessed and re-used. 

A finished roll of film, paper, laminate or labelstocks.

The release liner treatment material - usually silicone - that is coated onto the backing paper or film and which enables pressure-sensitive face materials or labels to be readily removed from the protective release liner prior to application. 

The release liner or backing is that component of the pressure-sensitive laminate construction which functions as a protective carrier the pressure sensitive adhesive. It is separated from the adhesive and the face stock prior to the label being applied to a container, pack or other surface. 

Usually refers to an adhesive label that has been removed, but leaves a portion of the adhesive behind on the previously labelled surface. The adhesive label does not remove cleanly.

A press that normally prints and converts label material from a roll and then rewinds it on a roll. Printing may be by any printing process or combination of processes. The web passage and printing units in a rotary press may be arranged in a variety of ways - in-line, common impression or stack. 

Printing operation that uses a cylindrical impression cylinder and a cylindrical printing plate (or sleeve). The web or sheet of labelstocks passes between the two cylinders to be printed. 

A pressure-sensitive adhesive that is based on natural or synthetic rubber. The adhesive may be coated as a hot-melt, solvent or emulsion. 

These are blends of elastomers and tackifying resins, which provide a wide range of pressure-sensitive adhesives for different applications. Rubber-based pressure-sensitive adhesives can be formulated as solvent-based, emulsion or hot-melt systems.

Inks are a perfect medium to provide authentication or brand protection features on labels and packaging because almost all packs and labels will be subjected to a printing process of some sort. Thus, inks that provide some kind of special security or authentication features can offer an effective solution to security problems. 

Papers which include one or more special identification or authentication features, such as metallic strips, threads, coloured fibres, reactive dyes, planchettes or watermarks so as to assist in detecting fraud and in preventing counterfeiting. They are papers which are impossible or difficult to reproduce and/or that provide evidence of tampering. Certain security label papers may contain authentication or identification features. 

A roll of pressure-sensitive material with a single ply that has adhesive on one-side and a release coating on the other side. When the roll is wound up the face stock functions as the release surface. This describes most tape products, but also so-called 'linerless' or 'backingless' labels. 

The time required under specified conditions to slide a standard area of pressure-sensitive adhesive stock from a standard flat surface in a direction parallel to that surface.

Used to describe the cutting of a continuous web of stock using an action similar to the action of scissors. 

A method used to separate adhesive to adhesive bonded materials by forcing the interfaces to slide over each other. This provides an indication of the cohesive strength of the adhesive.

A paper coated with silicone that ensures that the label face material and the matrix (waste face material after die-cutting) can be readily removed from the backing paper of a pressure sensitive laminate. It also protects the adhesive against any environmental influences which may otherwise adversely affect its efficacy. 

The action of cutting rolls of labelstock to specified widths on a slitting machine. Slitting is undertaken using either stationary or rotary knives or blades in a machine with roll unwind and rewind devices, tension control and web tracking. 

An adhesive whose components are dissolved in organic solvents for coating purposes, e.g. the adhesive coating on the self-adhesive label.

The force needed to remove a pressure-sensitive adhesive from a specific substrate under specific conditions. Also, a term used to describe particularly high adhesion between a specific adhesive (or class of adhesives) with specific types of substrates. 

The material, stock, unsupported film or other material upon which a coating of adhesive, silicone or primer is applied, or on which labels are printed. The surface to which a label is applied. Label stock converting/laminating companies also refer to the face stock in the construction as the substrate. 

Labels produced on heavy paper, card or special tag stock with die-cut holes so that the labels can be folded over a packaging material - as in a header or hanger label.

Strong grade of paper board or synthetic material with good bending/folding characteristics, high strength, tearing resistance and selected for printing items where durability is expected, together with a device for attaching the tag to a product. Used to mark or identify items, such as clothing, sacks, agricultural or garden products.

These are used to ensure that products are 'tamper evident' when displayed at the point of sale. There is a wide-range of tamper-evident solutions now used in the bottling sector, including tamper-evident closures, seals or stamps.

A paper coated with a heat-sensitive chemical coating that enables an image to be formed in areas heated by a thermal print head consisting of very many miniature heating elements evenly distributed along its printing width. These elements are selectively heated by pulses of energy which create points or dots of black (other colours are possible with appropriate paper) in the thermal coating and these dots create the image required from the computer's memory. 

A face paper or pressure-sensitive labelstock that has been specifically designed to accept heat-activated ink from the ribbon of a thermal transfer printer.

The ultimate adhesion available from a pressure-sensitive, determined by the force necessary to remove strips of tape from a surface after an extended period of time. 

The development of UV flexo printing in the narrow-web sector began in the early 1990s. Today, it is a process capable of achieving near-offset quality economically, while retaining the characteristics of a relief printing process. UV flexo inks are thicker and have a higher viscosity than conventional flexo inks. 

Many in-plant logistics systems - warehousing, distribution, shipping, storage, tracking etc. - use labels that are printed with variable data. This variable information printing (VIP) may be in the form of variable text, bar codes, sequential numbers, batch codes, date codes etc.

A strong, tough paper with a high quality appearance. Vellum has become the generic term for very smooth uncoated wood-free paper.

These are anti-tamper label products, usually polyester-based, that are applied to a labelling surface and when attempts are made to remove the material from the labelling surface, the pigmented or metalised layer on the back of the label - between the polyester and the adhesive - fractures to leave a message on the labelling surface and the same message in relief on the back of the polyester.

A pressure-sensitive adhesive in which all the components of the adhesive are soluble in water. 

The degree to which water vapor can pass through a substrate which is intended either as a supporting surface for a self-adhesive label or is itself a self-adhesive material.

A continuous roll of flexible material, usually paper, plastic film, foil or laminate in a roll form. Continuously wound rolls or reels are used on web-fed printing presses, coating and laminating lines and converting machines. The webs may be rewound for subsequent operations, slit into narrower webs or rolls, despatched to customers, or cut into separate sheets. Web-fed presses may be referred to as narrow-web or wide-web according to the width of the web being printed and converted. 

The brand name for dry toner-based digital colour printing systems manufactured by Belgian company Xeikon International. Xeikon offers modular finishing solutions from roll-to-roll finished output to near-line finishing, including UV-coating, die-cutting and waste striping.