DON’T STAY IN DOUBT, EXPAND YOUR KNOWLEDGE
We have gathered all the words used in the daily routine of those who work with labels, tags, and adhesives in general. Make the most of our glossary and consult it whenever you have any questions about a term.
Abrasion Resistance: The ability of a label surface, including its material, print, and protective coatings, to withstand friction and wear.
Abrasiveness: The tendency of a particular paper or ink to cause grinding or wear through friction.
Absorption: The property of paper to absorb liquids or vapors. In optics, it also refers to the partial suppression of light passing through a transparent or translucent material.
Accelerated Aging: A testing procedure in which labels are exposed to controlled environmental conditions to predict their natural aging behavior.
Acrylic Adhesive: A pressure-sensitive adhesive based on acrylic polymers, offering excellent stability for outdoor applications.
Adhesion: The bond or attachment created as a result of contact between two surfaces.
Adhesive: A substance that sticks or bonds to a surface.
Adhesive Bleed: The unwanted flow of adhesive beyond the edge of the release liner or onto the application surface.
Adhesive Failure: Partial or complete separation of a label from the substrate to which it has been applied.
Adhesive Mass: Another term for adhesive.
Adhesiveness: The force required to remove a pressure-sensitive self-adhesive material under specified conditions.
Adhesive Transfer: The transfer of adhesive from its normal position onto the surface from which it has been removed.
Aging: Changes that occur in a material over time.
Anchorage: The stability or bond strength between an adhesive and the face material itself or a stable anchor coating.
Application Temperature: The recommended temperature range at which a pressure-sensitive material should be applied to achieve optimal adhesion.
Barrier Coating: A coating applied to the reverse side of the face material to prevent adhesive penetration, improve adhesive anchorage, and enhance overall performance.
Biaxially Oriented Film: A film stretched in both the machine direction and the transverse direction to improve its physical properties compared with non-oriented polypropylene.
Body: The resistance of an adhesive to flow.
Bond: The adhesion of a pressure-sensitive material to the substrate on which it has been applied.
BOPP: Biaxially Oriented Polypropylene.
Burst Strength: The pressure required to rupture a paper when tested under specified conditions. It is primarily determined by the paper’s tensile strength and elongation.
Caliper Gauge: An instrument used to measure the thickness of a sheet of paper, typically in thousandths of a millimeter.
Cellulose: A substance found in plant cells. Its only solvent is Schweitzer’s reagent. When treated with sulfuric acid, it produces vegetable parchment.
Chemical Pulp: Cellulose pulp containing no more than 10% lignin.
Chemical Resistance: The ability of a pressure-sensitive material to resist deterioration caused by chemical substances under specified conditions.
Clear Coating: A transparent protective varnish applied to the printed surface of a pressure-sensitive label to protect it from abrasion, sunlight, chemicals, and moisture.
Coated Paper: Paper coated with calcium carbonate, china clay, pigments, and additives that seal the surface pores, producing a premium printing paper.
Coater: Equipment used to apply adhesive to substrates and manufacture pressure-sensitive materials. It typically consists of an unwinding station, coating units, rollers, drying ovens, and a rewinding station.
Coating: A material applied to form a protective or decorative film on a surface.
Coat Weight: The amount of adhesive applied per square meter (g/m²).
Cohesion: The internal strength of an adhesive. It represents the adhesive’s resistance to tearing or failure when labels are removed or subjected to stress.
Cohesive Strength: The internal bonding strength of an adhesive. It measures the adhesive’s resistance to forces acting parallel to the surface.
Color: The result of the selective reflection of light wavelengths between 400 and 700 nanometers, making it visible to the human eye. It is based on the decomposition of white light.
Color Fastness: The permanence or stability of color. The ability of a label to retain its original color during normal storage or resist color changes caused by exposure to light, heat, or other harmful influences.
Conditioning: The process of exposing a material to specified temperature and relative humidity conditions for a predetermined period.
Conformability: The ability of a label to conform to the contours of a surface due to its low cohesive resistance.
Core: A metal, wood, or compressed paper tube inserted into the center of a finished paper roll to support and protect it.
Cracking: A series of cracks in a varnish coating or plastic face stock, usually caused by repeated expansion and contraction due to temperature fluctuations or excessive solvents in the ink system.
Cracking: The presence of fine cracks in varnished, lacquered, or film-coated surfaces.
Cutter: A sharp cutting disc used to cut paper into predetermined sizes.
Debossing: An image pressed below the normal surface of the label.
Degradation: The occurrence of cracks, scratches, bubbles, color fading, or other forms of film deterioration.
Delamination: The separation of a material into layers.
Deterioration: Changes in the properties of an adhesive caused by aging over time.
Die: A tool or device used to cut materials into a specific shape.
Die-Cutting: The process of cutting only the face material into the desired shape (such as labels) without cutting through the release liner.
Dimensional Stability: The ability of a material to resist expansion and contraction under varying environmental conditions.
Direct Thermal: A printing technology that uses heated printhead elements to selectively activate a heat-sensitive coating on the face material, creating the printed image.
Double Cut: A finishing operation used for jobs that require a final trimming step after separation and other finishing processes.
Dryer: A steam-heated cylinder used to dry paper during the manufacturing process.
Dwell Time: The period during which a pressure-sensitive material remains applied to a surface before performance or removability testing.
Edge Lift: The tendency of the edge of a label to lift away from the substrate. Edge-lift resistance depends on the adhesive bond strength and the flexibility of the face stock.
Elmendorf Tear Test: A standardized test used to measure the tear resistance of paper.
Elongation: The increase in the length of a material resulting from stretching until its breaking point.
Embossed Finish: Paper with a raised or recessed surface pattern that resembles materials such as wood or fabric.
Embossing: Also known as raised embossing, a process that creates a raised or elevated image on the label surface.
Emulsion: A dispersion of fine droplets or particles of one liquid within another liquid.
Eucalyptus: A tree widely used in papermaking, rich in highly volatile essential oils and characterized by its distinctive aroma.
Face Material: Any paper, film, fabric, or metal laminate suitable for manufacturing pressure-sensitive materials. In the finished product, it is bonded to the adhesive layer and becomes the functional part of the label.
Face Stock: The printable surface of a pressure-sensitive material that is ultimately converted into a label, sticker, tag, or display.
Film: A polymeric material such as vinyl, polyethylene, polyester, or acetate used as face stock.
Film Coating: The application of a lightweight pigmented film to a surface.
Final Trim: The final trimming operation that brings a printed product to the dimensions specified by the customer.
Finish: A property determined by the texture and gloss level of a film’s surface, whether glossy or matte.
Fish Eye: A circular or eye-shaped defect that appears in a coating.
Flexibility: The property of a face stock that allows it to conform to curved surfaces.
Flexographic Printing: A rotary relief printing process.
Flow: The ability of ink to spread evenly across the surfaces of the printing cylinders.
Fluorescent Paper: Paper coated with fluorescent pigments that not only reflect visible light but also absorb and re-emit light at longer wavelengths, resulting in enhanced brightness.
Fold: A distortion in the material that interrupts the continuity and smooth winding of a roll.
Food-Contact Adhesive: An adhesive that complies with applicable regulations governing direct and indirect contact between labels and food products.
Full Cut: A cut made completely through the pressure-sensitive material (face stock, adhesive, and release liner).
Glassine: A supercalendered, smooth, dense, translucent paper manufactured primarily from long-fiber chemical wood pulp.
Glassine Paper: A supercalendered, smooth, dense, translucent paper manufactured primarily from long-fiber chemical wood pulp.
Gloss: The property of a surface to reflect light.
Gloss Coated Paper: Coated paper whose surface becomes smooth and glossy after contact with polished calender rolls during manufacturing.
Grain Direction: The direction of the paper fibers as they flow during paper manufacturing. Both the face stock and release liner follow the same grain direction in pressure-sensitive material production.
Gravure Printing: A printing process in which finely engraved recessed cells carry more ink than the surrounding surface.
High Coat Weight: A self-adhesive product containing a higher amount of adhesive per square meter, generally used on irregular surfaces such as corrugated cardboard boxes and plastic drums.
High Tack: An adhesive with a high degree of initial adhesion upon first contact.
High-Tack Adhesive: An adhesive that provides a high level of initial adhesion upon first contact.
High-Temperature Adhesive: An adhesive designed to withstand environments with temperatures typically above 90°C (194°F).
Hot Melt: An adhesive formulated from natural or synthetic rubber.
Hot Stamping: A decorative process in which an image is transferred to a substrate using a heated embossed die.
Impression Cylinder: The cylinder that transfers the image to the paper, either directly from the printing plate or via the blanket in offset printing.
Impurities: Small pieces of raw wood or other contaminants found in the finished paper.
Inhibitor: A substance used to extend the shelf life of certain adhesives by slowing the rate of chemical reactions.
Initial Tack: Also known as initial grab, the stage at which an adhesive has sufficient bond strength to hold surfaces together.
Ink Cracking: A printing defect caused by improper ink drying, in which the pigment disperses because the ink vehicle is absorbed too quickly by the paper.
Ink Head: The part of a printer that stores and supplies ink to the ink rollers.
Inkjet Printing: A printing method that deposits liquid ink onto a substrate in microscopic droplets.
Kraft Paper: Paper produced from sulfate wood pulp.
Label: The functional portion of a pressure-sensitive construction consisting of the face stock and adhesive, die-cut into various shapes and sizes for application to different substrates.
Label Applicator: A machine that automatically applies labels to a product.
Label Construction: The combination of the face material, adhesive, and release liner used to manufacture pressure-sensitive labels.
Lamination: The process in which the release liner is coated with silicone and adhesive before being laminated to the face stock to create a pressure-sensitive material.
Laser: A narrow beam of light capable of producing electronic images under computer control or through fax transmission.
Laser Printing: A non-impact electrophotographic printing process that uses a laser beam to create a latent image on a photoconductive drum, attracting toner that is then fused onto the printing surface.
Letterpress Printing: A printing process in which ink is transferred from raised type or rigid printing plates onto a substrate.
Lithographic Paper: Paper with a smooth finish on at least one side, specifically designed for lithographic printing.
Long Fiber: Fiber obtained from certain pine species, approximately 3 mm in length, commonly used in printing and writing papers.
Low-Temperature Adhesive: An adhesive formulated to provide reliable bonding on refrigerated and frozen materials.
Machine Direction (MD): The direction in which cellulose fibers align as the paper travels through the paper-making machine.
Matrix (Waste Matrix): The waste portion of the face stock and adhesive removed during the die-cutting process.
Matte Finish: A non-reflective, dull surface without gloss.
Mechanical Pulp: Pulp produced by mechanically separating wood fibers using water-lubricated grinding stones under high pressure.
Mechanical Pulp Paper: Also known as newsprint, paper produced by mechanically grinding and refining wood.
Memory: The property of a material that causes it to return toward its original dimensions after being deformed.
Metalized Paper Laminate: A metallic foil laminated to paper and used as a face stock material. The foil is typically coated to improve ink receptivity.
Metallized Film: A plastic or resin film coated with an extremely thin layer of metal.
Meter (m): A unit of length equal to 100 centimeters or 1,000 millimeters.
Micrometer: A precision instrument used to measure film thickness with an accuracy of 0.01 mm.
Micron (µm): A unit of length equal to one thousandth of a millimeter (0.001 mm), commonly used to specify film thickness.
Migration: The movement of one or more components of an adhesive into the substrate or face material, or the movement of components from the face material or substrate into the adhesive or ink.
Moisture Resistance: The ability to resist the absorption or penetration of moisture.
Mottling: A non-uniform color appearance on a sheet of face material or a finished label.
Natural Aging: The changes experienced by a pressure-sensitive material as a result of normal environmental exposure.
Non-Oriented Film: A film that has not been stretched to align its polymer chains and improve its physical properties.
Nylon: A plastic film with high resistance to oil and grease, also used as filament reinforcement in adhesive tapes.
Offset Paper: Paper made from 100% bleached chemical pulp with surface sizing. It offers excellent dimensional stability, minimizing water absorption before, during, and after printing.
Offset Printing: An indirect printing process in which the image is transferred from a flat printing plate to a rubber blanket and then onto the substrate.
Opacity: The property opposite to transparency in paper or film. It prevents dark printing from showing through to the reverse side.
Opening (Split): A deformation in which one layer separates from another, creating a gap or opening.
Orientation: The alignment of the crystalline structure of polymeric materials to produce a highly uniform structure.
Overlaminate: A transparent film applied over printed graphics to provide protection and enhance their appearance.
Overlap: A label designed to wrap completely around a container so that one end overlaps the other.
Oxidation: The deterioration of an adhesive film caused by exposure to the atmosphere.
Pallet: A platform used for storing and transporting paper.
Paper: A homogeneous sheet of cellulose fibers formed from an aqueous suspension, bonded together through fiber interlacing and additives.
Paper Conditioning: The process of placing paper in small stacks on special racks to allow proper air circulation before printing.
Paper Size Format: The standardized paper size system proposed by the Deutsche Industrie Norm (DIN) and adopted worldwide.
Paper Unit of Measure: Grams per square meter (g/m²).
PE: Polyethylene.
Peeling: The spontaneous lifting or separation of an adhesive tape or label from the surface to which it was applied.
Penetration: A change in the appearance of the face material caused by the migration of one or more components from the adhesive or substrate.
Perforation: A series of small cuts or slits made in labels or face stock to facilitate tearing or separation.
Permanent Adhesive: A pressure-sensitive adhesive characterized by its strong, long-lasting bond.
PET: Polyester.
Pigment: Solid particles used to provide color, body, and opacity to printing inks.
Plastic: A material made from polymers, including both natural and synthetic types, that can be molded into specific shapes under heat and pressure.
Plasticizer: A substance added to materials to increase flexibility, elongation, and overall processability.
Plate Cylinder: The cylinder on which the printing plate is mounted.
Polyester: A film with excellent resistance to moisture, solvents, oils, and many other chemicals.
Polyethylene: A strong, flexible extruded film.
Polymer: A material consisting of synthesized organic resins, although the term may also refer to natural substances such as starch, sugar, cellulose, and natural rubber.
Polypropylene: A polyolefin plastic with properties similar to polyethylene but offering greater temperature resistance and higher strength.
Porosity: The density and absorbency of an adhesive surface, determining its ability to absorb adhesive.
Pressure-Sensitive Label: A piece of paper or film coated with a thin layer of pressure-sensitive adhesive. It consists of three components: the face stock (the printable surface), the pressure-sensitive adhesive, and the release liner.
Pressure-Sensitive Material (Self-Adhesive): Paper, film, or another material that adheres through applied pressure, without the need for additional glue. Simply remove the release liner and press the material onto the desired surface.
Pressure-Sensitive Material Unit of Measure: Square meter (m²).
Protective Coating: A coating applied over the printed surface to protect the label from abrasion, sunlight, chemicals, moisture, or a combination of these factors.
Recycling: The reuse of trim waste by blending it with virgin materials before reprocessing, typically in blow molding operations.
Release: The force required to separate the face stock from the release liner, typically measured in kgf/in or kgf/cm.
Release Force: The force required to separate the face stock from the release liner, typically measured in kgf/in or kgf/cm.
Release Liner: Also called a liner, a paper or film treated with silicone through a polymerization process to protect the adhesive side of a pressure-sensitive product.
Release Liner (Liner): A paper or film coated with a release agent that protects and supports the adhesive layer until application.
Removability: The characteristic that describes the ease with which a pressure-sensitive material can be removed from a substrate. A removable label can be removed without damaging or staining either the substrate or the face material.
Removable Adhesive: A pressure-sensitive adhesive designed to be removed after application without leaving residue.
Repositioning: The process of relaminating die-cut labels onto a different position on the release liner.
Residue: Adhesive remaining on the substrate after a label has been removed.
Resin: A natural or synthetic polymer with an amorphous structure and no distinct melting point.
Rewinder: A machine designed to remove material from the reel, trim the edges, rewind it into rolls, and cut it.
Rewinder: A machine that unwinds material from the master roll, slits it, and rewinds it into smaller rolls.
Rewinding: The process of transferring material from one core to another to produce rolls with the desired width, diameter, and winding tension.
Roll: A continuous sheet of manufactured material.
Roll Tension: The pulling force applied to a paper roll as it moves through a roll-fed printing press.
Rotary Press: A printing press that uses plates mounted on cylinders and continuous rolls of paper, commonly used for newspaper printing.
Rubber-Based Adhesive: Also known as *hot melt*, an adhesive formulated from natural or synthetic rubber.
Scanner: A device used to separate and reproduce colors and tonal values accurately.
Screen Printing: A printing method in which ink is forced through the image areas of a stretched mesh using a squeegee or air pressure.
Sealant: A thick adhesive, typically with low cohesive strength, used to fill gaps and prevent the passage of liquids or gases.
Service Temperature: The temperature range a pressure-sensitive label can withstand after it has been applied to the substrate for at least 24 hours.
Setoff: Also known as offsetting, the unintended transfer of wet ink from one printed sheet onto the next sheet stacked above it.
Shear: The time required for a pressure-sensitive adhesive to achieve bond strength after application, or the adhesive’s resistance to shear forces during curing.
Shearing: The complete cutting of a material.
Sheeting: The process of converting pressure-sensitive material into finished label sheets of a specified length using a rotary press.
Short Fiber: Fiber obtained from plants such as eucalyptus and sugarcane, approximately 1 mm in length, commonly used in printing and writing papers.
Shrinkage: The reduction in the dimensions of a pressure-sensitive material.
Silicone: A material applied to the release liner to create a non-stick surface that protects the adhesive while maintaining its tack and facilitating easy label release.
Silicone Coating: The process of treating a release liner with silicone resin through polymerization.
Skid: A protective shipping platform or package used to transport large quantities of paper sheets.
Slitting Unit: Equipment that cuts material into narrower widths using rotary knives.
Smudge Resistance: The ability of a printed paper surface to resist ink smearing, smudging, or staining.
Solvent Resistance: The ability of an adhesive material to withstand exposure to specific organic solvents.
Specific Adhesion: The force required to remove a pressure-sensitive label from a substrate under specified conditions.
Splice: A method of joining paper or plastic webs in a pressure-sensitive roll to create a continuous production web.
Split Face: A break, tear, or crack in the face stock designed to facilitate label removal.
Square Meter (m²): The standard unit of area used to measure pressure-sensitive materials.
Stiffness: The ability of a material to resist bending or flexing.
Stretching: The elongation of a pressure-sensitive material when a label is removed from a substrate, face stock, or matrix.
Substrate: The surface to which an adhesive or label is applied.
Tack: The ability of an adhesive to bond to a surface upon initial contact.
Tackifier: A resin or additive incorporated into an adhesive to improve its initial tack.
Telescoping: A roll deformation in which the material shifts sideways, creating gaps between the layers.
Temperature Resistance: The ability of a pressure-sensitive material to maintain its performance over a specified temperature range, including during printing.
Tensile Strength: The force applied parallel to the plane of the specimen that is required to break a paper of a specified width and length under defined conditions.
Thermal: Relating to the effects of heat or temperature.
Thermal Transfer Printing: A printing process that uses a temperature-sensitive ribbon. Heat and pressure transfer the ribbon coating onto a printable surface, producing the desired image.
Thickness: The distance between two surfaces, measured under slight pressure with a precision gauge and typically expressed in thousandths of an inch.
Timbó Board: A board used during die-cutting as a make-ready backing placed between the pressure-sensitive material and the press bed to achieve proper die pressure.
Toner: The powdered colorant used in laser printing to produce images and text.
Toxicity: The physiological effects resulting from the absorption of toxic substances through the skin, mucous membranes, or respiratory system.
Transfer: The movement of material from its original position to another location during unwinding or removal.
Transfer Tape: A pressure-sensitive adhesive applied without a face stock, carried on a release liner coated on both sides.
Transparency: The property of a material that allows light to pass through so that objects behind it can be seen clearly.
Ultimate Adhesion: The maximum adhesion achieved by a pressure-sensitive label. It is the force required to remove the label from a substrate after an extended period.
Ultimate Tack: The stage at which the adhesive has fully bonded to the substrate.
UV: Abbreviation for ultraviolet. Refers to a printing process that uses UV-reactive inks cured within fractions of a second.
UV Resistance: The ability of a material to resist the harmful effects of sunlight, particularly ultraviolet radiation and infrared wavelengths.
Varnish: A solution or suspension of one or more materials that forms a protective and decorative film through oxidation, polymerization, or evaporation.
Vegetable Parchment: A paper similar to animal parchment that is resistant to oil and water. It is produced by treating paper with sulfuric acid to gelatinize its surface, followed by washing and drying.
Vinyl: Plasticized polyvinyl chloride (PVC), a durable plastic film resistant to oils, chemicals, and solvents.
Watermark: A design impressed into paper during manufacturing by the patterned surface of a textured roll.
Wax Coating: The application of paraffin or another type of wax to a sheet of paper.
Weather Resistance: The ability of a label or tag to withstand exposure to environmental and climatic conditions.
Wood-Free Paper: Paper manufactured from 100% chemical cellulose pulp.
Wrinkling: Wrinkles or folds that may develop in a pressure-sensitive product due to environmental conditions such as temperature and relative humidity.
Yellowing: The gradual development of yellow or brown discoloration caused by changes in the original color of a self-adhesive label.
