| Tack | The feeling of stickiness obtained when the surface of an adhesive is touched or when a label is applied to a surface and quickly pulled away. |
| Tackifier | An additive used to improve the stickiness or tack of an adhesive. |
| Tackiness | The stickiness of the adhesive. |
| Tactile image | A raised image, normally in the shape of a triangle, which is embossed or produced thermally. Used as a warning for persons having restricted vision, on packs containing hazardous substances. |
| Tag | Any identification which is only partly fixed to the item. |
| Tag image file format (TIFF) | A format for storing and importing images into a layout. |
| Tamper evident labels | Labels that after application will fragment or split (sometimes leaving a VOID message) when removal is attempted. |
| Tamperproof label | A label made of a substrate that will destruct with any attempt to remove it from the container. |
| Tear strength | The property of a material that is measured by the force required to tear it under specified conditions. |
| Telescoping | The slippage of successive winds of a roll of material so that the edge is conical rather than flat. |
| Tensile strength | The maximum load in tension that a material can stand without failure. |
| Tension | The mechanical control of material in roll form between the unwind and rewind stations. The condition caused by a force operating to extend, stretch, or pull apart. |
| Tertiary colours | Those obtained by mixing two secondary colours. |
| Test run | Pre production runs to test new materials or labelling situations. |
| Therimage | A trade name for a label which is printed in reverse on a laquer coated paper. A heat activated adhesive is coated over the image and the complete decoration is removed by applying heat through the back of the paper carrier. |
| Thermal | Refers to the use of heat in any process. |
| Thermal dye sublimation | A form of thermal printer where the dyes are vaporised and float onto the material being proofed. |
| Thermal expansion | The diameter of rollers, when warmed up through running, will increase in diameter. If this increase is not controlled and allowed for, a loss of register is likely to occur. Applies especially to rotary cutting tools and steel print cylinders. |
| Thermal transfer | Uses digital data to drive thermal printheads that melt spots of dry thermoplastic ink on a donor ink ribbon and transfer them to a receiver to produce colour images. |
| Thermochromatic | Inks which change colour when exposed to a change in temperature. Some revert back and some remain changed once the temperature is returned to normal. |
| Thermographic | A printing method utilizing heat and specially coated paper to form an image. |
| Thermoplastic | A substance capable of being softened by heat. |
| Thickness | The distance between the two surfaces of a paper or filmic material, measured under specified conditions. |
| Thixotropy | Gel - fluid reversible change of viscosity between resting and stressed state. |
| Threading | The function of passing the web of material through the label press prior to commencing a run. The path followed by the web will vary according to the sequence of printing and converting required. |
| Tie | The term used to identify the uncut portions of a perforation. |
| Tight release | When the level of release between the backing and the label makes the label difficult to remove. Automatic application would prove difficult. |
| Tints | The strength of colour evenly spread over an area. |
| Titanium coating | An extremely hard coating added to rotary tooling to increase life and enable it to convert tough plastics films. |
| TLMI | Tag and Label Manufacturers Institute. The national association for label printers covering the USA. |
| Tolerance | The specified variation from mathermatical perfection permitted. |
| Tolerances | Specified variations in colour, register, size, and other parameters relating to the printing and converting processes. Should be stated in numerical terms whenever possible. |
| Toner | Imaging material used in electrophotography and some off-press proofing systems. |
| Tool steel | The steel containing a high proportion of chrome and carbon from which rotary tooling is made. |
| Tooth count | Refers to the number of teeth around the circumference of a gear wheel. Each tooth count equals a repeat length when applied to the gears for rotary dies or printing cylinders |
| Topcoat | A surface coating to a material designed to improve ink key, opacity, or prevent migration. |
| Toxicity | Relates to the poisonous qualities contained by any material. |
| TQM | Total Quality Management. A way of managing a business to ensure complete customer satisfaction at every stage, internally and externally. |
| Tracking | Any side to side movement of the web as it passes through the press. |
| Transfer adhesive sandwich | A pressure sensitive adhesive layer, sandwiched between two release liners which have differential release properties enabling them to be removed successively in order to allow the unsupported adhesive alone to be applied to a substrate. |
| Transfer roll | A plain or engraved roll which rotates in a bath of liquid and transfers a specified amount of the liquid to a subsequent roller. |
| Translucent | Material that transmits light in a diffused manner so that objects cannot be clearly seen through it. |
| Transparent | A material which transmits light clearly and through which objects may be clearly identified. |
| Transparent ink | A printing ink which does not conceal the colour beneath. Process colours are transparent in order that they may blend together to form other colours. |
| Transparent label | A label printed on clear material and coated with clear adhesive in order that light or visual objects may be clearly defined through it. |
| Transpose | To exchange the position of a letter, word, or line with another letter, word or line. |
| Trim | The edge waste from a master reel of from ex stores stock. |
| Tunnel | The compartment through which the web passes for drying or curing after printing or coating. |
| Turner bar | A stationary bar, set at 45 degrees to web direction, and over which the web is passed when it is required to turn it over for printing, coating, slitting, or punching from the reverse side. |
| Type high | The nominal height of metal type (0.918 inch). |
| Type manipulation | Software programmes which facilitate the manipulation of standard typefaces in order to create special effects. |
| Tyvek | Du Pont's brand name for a spun bonded polyolefin material frequently used as a face stock when extreme strength and durability are required. |
| T.I.R | Total Indicated Runout. Indicates the degree of misalignment between the centre of a shaft and the diameter of the cylinder it supports. |