D
Data compressionData compression is used to compress and thus reduce the size of data, either to save memory or transmission time. There are either lossless compression methods (such as ZIP) or lossy compression methods (such as JPEG or GIF).
Digital printPrinting method that doesn't need a master. Instead, it uses a digital file that is directly transfered to the print product, thus making it possible to print different images on every sheet of paper. You can, for example, personalize each print and insert the name of each recipient of a promotion campaign. You can also offer "print on demand", compiled of variable data. The huge advantage of this method is that you can produce small editions cost efficiently.
dpiAbbreviation for dots per inch. dpi is the measurement unit for both prints and screens. It indicates the point density or the amount of dots per inch. Colloquially one can also use the word "resolution".
P
PaginationThe application of page numbers to the pages.
Paper wasteFaulty prints, thrown away paper, damaged paper.
PerforationThe perforation of paper or cardboard along a line. Small holes or slits are punched out with steel combs or punch down tools. Perforations usually are used to provide a simple separation of single pages or segments of a page.
PrepressAll work steps that are neccessary to produce a master, such as layout, image editing, page and sheet assembly or the exposure of films for the production of printing plates.
Printing methodsThere are different printing methods, such as offset printing, silkscreen printing, gravure printing or letterpress. They can be used to influence different variables, such as different color palettes, printing substrates or even the expenses.
ProofA test print to control the tonal and colour values and to compare the quality of the proof with the quality of the template. The print result is directly monitored at the machine. Today though there are many different proof methods that are cheaper and quicker.
R
RasterMany printers and imagesetters for offset printing can only print black, they can't print grey scales. An image that contains grey scales thus has to be rastered in order to simulate an image in full colour. When you, for example, have a black-and-white image, the brighter image values are produced with small picture elements and the darker image values are produced with bigger picture elements. When every element is small enough you get a grey colour impression. When you use four-colour printing all four colours are used to raster.
Register marksRegister marks are small cross hairs that are arranged on colour selections and printing plates. They are extremely important for an exact fitting, the arrangement of the printing plates and the exact printing of the colours. After the printing process the register marks are cut away.
ResolutionThe resolution is the measure of image sharpness. It indicates the number of picture elements (pixels, lines or dots) to be reproduced on a screen, a film or on paper per inch.