Printer's glossary

Uniform colour background - uniform background made in 100% with paint (ink) of one colour. In printing this is uniform printing surface.

Creasing - impressing a groove or grooves in spots where paper or cardboard is to be folded. This technique is used to make folding paper or cardboard easier to fold.

CMYK - (Cyan, Magenta, Yellow, Key - black) - a set of primary colours of inks commonly used in offset printing. By mixing them in appropriate proportions it is possible to get any colour (except white). Because due to impurities in inks it is impossible to create true black, the three primary colours were supplemented with black. Thanks to mixing these four colours it is possible to achieve full colour printing.

In this area we differentiate between:

4+4 – double-sided CMYK print

4+0– single-sided CMYK print

1+0 – single-colour single-sided CMYK print

1+1 – single-colour double-sided CMYK print

5+0 – single-sided CMYK print + one Pantone colour, etc.

Cromalin – also called proof, is a print used as a colour calibration model for a printing press.

Digital printing - a printing technique which does not use printing plates for printing directly from a digital file. It is done on a special machines whose logics resemble huge dye-sublimation printers with high technical parameters. Special inks (solvent inks) are resistant to weather conditions. Digital printing occupies the niche between plotter printing and traditional offset printing.

Offset printing - a flat printing technique which consists in indirect printing with greasy ink. The printing plate is a specially prepared offset plate.

Dpi - in raster graphics (bitmaps), the number of dots per inch which specifying the resolution of bitmap graphics. For offset printing the resolution of 300 dpi is usually used. In large-format printing 20-30 dpi is used for large projects and max. 150 dpi for small ones. Internet graphics uses the resolution of 72 dpi.

EPS - Encapsulated PostScript - computer graphics file format developed by Adobe Systems Inc., written in PostScript programming language.

Folding - folding a sheet of paper after printing in order to create a desired format with continuous numbering of pages.

Foil laminating - it is a type of lamination which consists in coating printed surfaces with plastic foil (mat or glossy) in order to additionally preserve the print and add aesthetic value. Foil laminating preserves the print against factors such as abrasion, folding, dirt, etc.

Paper grammage - weight of one square metre of paper in grams. We use various values of paper grammage from 80g - 350g.

Paper types – various paper types are used in offset printing, the most often used are:

- Offset paper – used in production of books, brochures, magazines, posters and packaging labels. The most common grammage of such paper is 90g - 150g.

- Chalk overlay paper – paper coated with a thin layer of white mineral pigment and glue. It is characterised by greater ink holdout.

- Decorative paper - a wide selection of commonly used decorative paper.

- Cardboard – used in production of stiff materials, i.e. folders, calendars etc.

Moire - undesired effect emerging in computer processing of raster graphics originals due to inappropriate overlapping of raster points, treated in images as a defect. It may happen during scanning of materials printed using the raster technique (offset printing) and in many cases it is difficult to remove.

Circulation - the number of copies of a printed material.

Prepress – in offset printing; it consists in exposing films - transferring the material from a computer to film (CTF) or plate (CTP) from which materials are printed.

PANTONE - special Pantone inks are the most commonly used colour models. These are special colours which cannot be created by mixing CMYK colours, e.g. golden, silver etc.

Perforation - a row of holes made during the printing process with a special tool in order to make tearing off a piece of paper easier.

POS - Point of Sale - promotional materials at the site of sale. Examples of POS may be various posters, hangers, coasters, leaflets and catalogues.

Raster - a structure which allows to convert continuous tones to dots (or other elements) which give the impression of shades of grey (or another colour). In case of classic screening (autotypical, AM - amplitude modulation) raster elements are placed at the same distance from one another making a fixed grid and they have different sizes. The larger the dots the more surface is covered and the image is darker. Classic raster is characterised by raster density. In case of stochastic raster (FM - frequency modulated) there is no fixed grid but dots of the same diameter (size) are placed at various distances from one another.

RIP- Raster Image Processor - hardware or software which converts data saved as PostScript to a raster image adjusted to the operating machine (imagesetter, printer etc). The raster image is adjusted to the resolution required for the device.

Bleed - area of print which goes beyond the edge of the sheet after trimming. Bleed ensures that the printed area will be matched to the edge of the sheet.

Punching / die-cutting - a bookbinding operation consisting in cutting a desired complicated shape of a paper product from paper sheets, cardboard or another material, which is not possible using a regular paper cutter. This is done using a cutting die, whose working part is a specially shaped blade which cuts the surface perpendicularly.

Tint - uniform colour printed background made of typesetter elements or an engraved plate. Tint is usually printed with bright ink on which text, image or initial is printed with dark ink.

Enriching - coating of printed sheets in order to enhance their resistance or for aesthetic purposes, e.g. varnishing or foil laminating. This allows to create glossy, mat or mixed (mat foil and glossy spot varnish) surfaces. Apart from visual effects it makes printed surfaces flexible and moisture resistance and protects them against abrasion.

We offer 4 techniques of enrichment:

- UV varnish –UV cured varnish , it may be divided into mat and glossy types

- Offset varnish – offset varnish which protects printed surfaces

- Mat foil – coating of a printed surface in order to make it more resistant and flexible; mat foil may also be mixed with spot varnish

- Glossy foil - coating of a printed surface in order to make it more resistant and flexible

Cutting die – a tool for cutting specific shapes usually from a printed sheet - a surface with fixed blades is pushed against the printed paper and cuts out the entire pattern (e.g. a box pattern) in one stroke. Often apart from cutting bars (cutting blades) there are creasing bars and sometimes perforating bars (perforating blades). Apart from the basic cutting function a cutting die may also crease (fold) or perforate. Classic cutting dies are made by placing cutting, creasing and perforating bars in a board (usually plywood) with grooves.

Trapping – a method for correcting fitting defects made during printing. If two objects are printed using two different units of printing machinery and are to closely fit together then there is a possibility that due to fitting mistakes there will be space between them (e.g. white printing paper will be visible). In order to prevent this from happening the objects are enlarged by 0,3-1 points. This way a common area is created, which is virtually invisible for an eye. Trapping is performed during computer preparation for printing. If the area of the object is enlarged then we are talking about spread. Trapping is usually used in line art graphics (drawing, graphics, text), not in photographs.

We use a water-based offset printing technique - it is an industrial type of flat printing, in which images are transferred from a flat printing plate to the printing surface through a plate cylinder covered with rubber. There are hydrophilic and hydrophobic spots on the printing plate which are moistened with water solution and ink respectively. There is repulsion between the water solution and offset ink - achieving balance between water and ink is important, so that water does not infiltrate to ink and vice versa. This is achieved by using right proportions of ink and water on the printing plate. The moistening solution consists in 85-95% of water.