Screen Printing Inks & Varnishes Glossary

You are bound to encounter a great deal of jargon and complicated terms when looking to get something professionally printed or even when buying your own ink. The following terms and phrases are used in most printing practices:

• Anti-offset powder – this is a powder that is sprayed over the surface of page as it is leaving the offset printer.
• Bleed – this is when the image or artwork extends past the trim line of page. If an image is “bled off”, it means that it is spread to the edge of the page and has no margins.
• Blocking – this is when inked or printed pages stick together in a pile and cause damage when separated. Causes of this are usually linked to too much ink being used or not enough anti-offset powder being used.
• Caliper – this is the measurement of the thickness of a piece of paper in thousands of an inch.
• Cartridge – this is a thick general purpose type of paper that is used for drawing, wrapping and printing.
• Cast coated – this is paper that has been coated with a high gloss reflective finish.
• Chalking – this is a powdered effect that is left on the page after printing has failed to complete and dry properly.
• CMYK printing – this is a process of printing where four colours of ink are used. These are cyan, magenta, yellow and key black. This particular printing process makes use of these colours in the exact order of the abbreviation (although variation must be allowed from print house to print house).
• Colour cast – this is an incorrect or unwanted colour that affects an entire image or part thereof.
• Colour separation – this is the process where artwork or images of a continuous colour tone are separated into the 4 process colours, ready for print production.
• Density (in reference to ink) – this refers to thickness of the layer of printed ink.
• Density range – this refers to the difference between the lightest and darkest area of a copy.
• Densitometer – this is a device that is used to control the density or balance of ink applied to a surface. This device is mainly used by printers and photographers.
• Die – this is a steel engraving stamp that is used to print an inked image onto paper. The engraving stamp is hardened and produces a top quality print result.
• Digital ink – this is an ink type that is used in a digital printer. There are solvent based and UV curable digital inks available on the market.
• DPI (Dots per Inch) – this refers to the resolution of an input device such as a printer, scanner or monitor. The DPI setting will affect the overall quality and clarity of the image.
• Eco-solvent ink - rapidly gaining popularity due to increased color quality, durability, and safety, and decreased cost.
• Fast colour inks – these are inks that are able to retain their density thus resisting fading after washing and exposure to the elements.
• Flat colour – this is any colour that is printed using only one ink. Many colours are printed with a four-colour ink process.
• Flexography – this is a method of printing by using rubber or plastic plates with raised images on a web press.
• Flexographic ink – these are fast drying, low viscosity inks. It is used to print packaging materials, paper, plastic, food containers, catalogues and more. There are 3 main types of flexographic inks namely water-based flexographic ink, solvent based flexographic ink and UV curable flexographic ink.
• Gravure ink – these are low viscosity fluid inks. This viscosity allows them to be drawn into a cylinder that is engraved, and is then transferred onto the substrate. This type of ink needs to be dried by being sent through a gas or electric drier.
• Hue – this is a specific colour such as green or yellow.
• Ink – An ink is a liquid that contains a number of pigments or dyes that are transferred onto a medium or substrate such as paper to produce an image or pattern.
• Ink balance – this is the relationship of dot grain density.
• Ink cartridge – this is a replaceable component. It contains the ink that is used by a printer and sometimes even includes the print head itself. All ink cartridges contain an ink reservoir and an electronic chip that communicates with the printer.
• Ink coverage – this is the extent at which ink covers a surface of substrate. This is often expressed in terms such as “light”, “medium” or “heavy”.
• Lithography – this is a printing method that makes use of plates. These plates have image and non image areas. Ink is usually attracted to the image areas and repelled by the non image areas. Non image areas are coated in water or silicon to repel the ink.
• Machine glazed paper – this is a type of paper that is rough on one side and highly glossy on the other. This type of paper is popular for making posters.
• Metallic ink – this is an ink that contains pigment and powdered metal which enables it to simulate metal.
• Mottle – this is what happens when an ink absorbs and dries unevenly or spotty.
• Offset printing – this is a type of printing technique where the ink is not transferred straight from the plate to the paper or substrate, but is transferred from plate to blanket to paper.
• Opaque ink – this is any ink that completely covers ink below it.
• Pantone colours – these are set colours easily found on a standard colour palette. By knowing the actual number of the pantone colour you want, designers and printers can perfectly match your art work to your desired end result.
• Print – the process of transferring an image, artwork or pattern onto a substrate or medium with the use of ink and various printing presses.
• Printing plate – this is in reference to any surface that carries an image that is to be printed.
• Resolution – this is the DPI (dots per inch) of a computer generated image. The higher the DPI, the better the quality of the image will be once it is printed.
• Screen printing – this is a form of printing that makes use of a woven mesh which is used to support a stencil (this is an ink blocking stencil). The stencil used blocks ink, leaving certain areas free for ink to be transferred onto a material or substrate. A squeegee is used to push the ink across the stencil which then forces the ink through the mesh. This creates a clear and top quality print finish.
• Silk screen supplies – these are the types of ink, accessories and tools that are required to create silk screen prints.
• Solvent - this is a liquid medium that is able to dissolve various other substances.
• Solvent based ink – ink that has a base substance that is able to dissolve other substance. This usually is a water based ink.
• Substrate – this is any material or surface that is to be printed on.
• Thermal inkjet printing – most inkjet printers use cartridges where each partition inside the cartridges reservoir is a heating element with a small metal resistor. When the printer communicates with the cartridge, a current is sent to the metal resistor which then makes it warm. This results in a drop of ink being forced out of the cartridge and onto the paper.
• Thermography – this is a printing process where slow drying ink is used. Once it is applied to paper a resinous powder is dusted over it. The printed paper is then sent through a heat chamber where the resinous powder melts and fuses with the ink. A raised surface is produced.
• Tint – this is an area of tone which is made up on a continuous patter of dots. This lightens the colour of the ink.
• Under colour removal – this is when cyan, yellow or magenta are removed from an image that is heavily covered to limit the amount of ink that is being applied. This ensures that there is no production problems encountered.
• UV ink – this is a type of ink that is able to intensify colour and produce an extremely high quality image when printed. This ink is popular as it is exceptionally quick drying. This type of ink is solvent free and is therefore more environmentally friendly than other inks. UV ink is a dual state substance. It is in fact a solid that remains in its liquid form until it is exposed to a UV light.
• UV Coating – this is a hard and somewhat shiny coating that is applied to paper and then set in place with exposure to UV light. This can be applied to the entire sheet of paper or just to certain areas on the paper.
• Varnish – this is a durable and hard coating that provides a transparent (or tinted finish) to a surface. Varnish is commonly used on paper and wood products.
• Water based ink – this type of ink is mainly used for printing paper, plastic, shirts and even towels. It is a water based substance with pigment suspended in it. This pigment then attaches to the surface or substrate when applied.
• Web printing – large rolls of paper are used for this printing process as opposed to single sheets of paper. These rolls of paper are fed through a printing press for best image results.
• Wide format printing – this is a printing method used for images or artworks between the sizes of 70” and 100”. A wide format printer is used for this and it is usually for the creation of banners, posters and signage.