Additive Primaries; Red, Green, and blue light. When all three additive primaries are combined at 100% intensity, white light is produced. When these three are combined at varying intensities, a gamut of different colours is produced.
Angle squeegee; The angle formed by the face of the squeegee in relation to the screen mesh. The higher the angle, the less the ink deposit (screen printing).
Aromatic Solvents; Organic solvents of a hydrocarbon structure.
Bitmap; Also called raster images. Bitmap images use a grid (the bitmap or raster) of small squares known as pixels to represent images. Each pixel is assigned a specific location and colour value. A bitmap image is resolution dependent. It contains a fixed number of pixels to represent its image data. Bitmap images are used to represent the subtle gradation of shaded and colours in photographs or painted images.
Bleed; Page elements that extend past the trimmed edge of the finished page. This ensures that when the pages are cut, there is no gap between the edge of the printed element and the edge of the page.
Blockout; To remove unwanted printing areas in the screen using a suitable medium/solution (screen printing).
Caliper; The thickness of a substrate or paper.
CMYK; Cyan, Magenta, Yellow, Black – known as the subtractive colour system; used by printing devices. Cyan, magenta, yellow, and black inks can be combined to reproduce a large range of colours.
Collate; The organising of printed sheets into a selected sequence.
Colour Management; Matching colours between an original image, scanner, monitor, colour printer and final press sheet.
Colour Separation; To separate artwork/copy/digital files into subtractive CMYK for printing.
Creasing; Bruising or indenting a line in paper, cardboard, etc., to facilitate folding.
Crop; To decrease the size of a picture or illustration by cutting away areas from the surrounding sides.
Crop Marks; Lines that indicate the outer trim areas of pages on a sheet.
Cure; An ink is completely dried, free from solvent when cured.
Cyan; A subtractive primary. One of the process ink colours for printing. Pure cyan absorbs all red wavelengths of light and reflects or transmits all blue and green wavelengths.
Decal; A screen printed waterslide transfer.
Densitometer; (1) A photoelectric instrument that measures the reflection density of colours.
(2) A transmission densitometer measures dot sizes on graphic arts film or continuous tone density on photographic film.
Dot; The individual element of a halftone. The size of the dot is indicated by the percentage of the area it occupies from zero to one hundred percent.
Dot gain; An increase in the size of the halftone dots resulting from film and plate exposure, tack or viscosity of printing ink, ink film thickness, machine pressure settings and internal reflections of light.
DPI; Dots per inch. A measurement of output device resolution.
Elliptical dot; Also called a chain dot. This halftone dot shape improves the gradation of mid tones and especially skin tones.
Epoxy; Normally a two pot ink used to bond to difficult surfaces.
EPSF; Encapsulated Post Script File: A file format for graphic shapes and objects that contains a complete PostScript definition of a file. It can also include a bitmap equivalent for the monitor. This format is widely used for transferring images from one type of document to another, e.g. from a drawing programme to a layout programme.
Extender base; Non pigmented ink, added to standard ink to make it transparent.
Finish; A term describing the characteristics of the surface of paper.
Flat bed; A scanner or plotter that transfers images by means of a flat plane rather than a revolving cylinder.
Floodcoat; The coating of an ink across the open areas of the screen mesh prior to printing. Floodcoating will enable consistency in colour and ink deposit (screen printing).
Font; A single style, size and weight of a typeface. For example, 12-point Goudy italics and 9-point Goudy roman are different fonts, even though they are members of the same type family.
Four colour process; Reproduction of an image by printing with the subtractive primaries of yellow, magenta and cyan plus black.
Gamut; The range of different colours that can be interpreted by a colour model or generated by a specific device.
GIF; Graphic Interchange Format. A compressed graphics file format widely used for internet publication.
Gold blocking; Hot foil stamping an image onto a book cover or substrate.
Gradation; The range of tones of an image from the highlight to the shadow.
Grain; (1) The direction that the fibres in a sheet of paper run. Indicative of the direction in which paper is made on a paper machine.
(2) In film terms, grain describes the textured effect of individual crystals of silver on the appearance of the image.
Greyscale; A continuous tone image comprising black, white and grey data.
Grid; A planned division of any area into related units of space. In electronic systems they are used to accurately position text and image information in page layouts.
Gripper; Metal clamp that grabs the leading edge of a sheet and controls its path through a printing press.
GSM; The grammage or weight of paper (gsm: grams per square metre).
Gutter; The blank space or inner margin between pages on the layout sheet.
Halftone; A printing process where colour intensity is controlled by the size of dots regularly spaced over the page.
Handcut stencil; Any stencil type hand cut and applied directly to the screen. (screen printing)
Hickey; An imperfection in the printed surface, due to dust etc.
Hue; The distinction between colours. White, grey and black are not considered hues.
Hue error; The difference between the ideal colour and the actual printing pigment.
Imagesetter; A high resolution printer used to prepare high-quality layouts on film or paper (usually at resolutions between 1,200 and 3,600 dots per inch).
Imposition sheet; A sheet of paper prepared as a guide to the prepress department, depicting the imposition and grip and lay edges required to produce a particular folding sequence.
Indirect Photostencil; A photographic stencil that is exposed, processed, then adhered to the mesh. (screen printing)
JPEG; Joint Photographic Experts Group. A lossy compression file format.
Knock up; To align one or two edges of a pile of sheets or material, so that they can be stacked neatly or processed accurately.
Lay edges; The two edges of a sheet which are placed flush with the side and front lays on a printing machine when feeding.
Lay mark; An area of ink on the edge of a sheet to make the lay corner easily identifiable. It appears on the side lay edge and is closer to the gripper edge than the trailing edge.
Lossy; Image compression that functions by removing minor tonal and colour variations, causing visible loss of detail at high compression ratios.
Magenta; A subtractive primary. One of the process ink colours for printing. Pure magenta absorbs all green wavelengths of light and reflects or transmits all blue and red wavelengths.
Makeready; All the necessary preparations for starting a new job on a printing press. This may include setting up the paper infeed and delivery, mounting plates and blankets, adjustments in the initial run and other requirements before the first good copy is approved.
Mesh; The image carrier in screen printing. Woven polyester, nylon or other material, available with different mesh counts (threads per cm).
Moire; A repetitive interference pattern caused by overlapping grids of dot lines.
Overs; In printing, the number of copies in excess of the required amount.
Pantone PMS; Pantone Matching System is an internationally standardised and catalogued list of widely used pre-mixed colours which are often specified by designers, graphic artists, typographers and printers of spot colour work.
Point: A typographical unit of measure, there are 12 points in a pica. Or in other words 1-point = .351 mm.
Pressure sensitive; Normally consisting of four layers of face stock, primer, adhesive and liner. Commonly called self adhesive sticker.
Process colour; Four colour work made up of various combinations of cyan, magenta, yellow and black, producing four colour separations.
Reducer; An ink additive used to change the viscosity of an ink, without affecting the drying.
Register; Having two or more colours, printing on the same paper, in exact alignment with each other.
Register marks; Crosshair targets on a colour separation to assist in aligning the image on the press.
Retarder; An ink additive used to change the viscosity of an ink and to alter the drying time.
Retensionable Screen; A screen whose mesh can be retensioned at certain points along the screen frame. This gives the printer the ability to adjust registration when shrinkage or stretch occurs. (screen printing)
RIP; Raster Image Processor. A combination of computer software and hardware that controls the printing process by calculating the bit maps of images and instructing a printing device to create the images.
Run; The number of finished copies required in a print job.
Set-off; The transfer of wet ink from one sheet to another.
Split back; A pressure sensitive material whose backing sheet or liner has been pre-cut to allow for easy removal.
Spot Colour; Printed colours created with specially mixed inks.
Step & Repeat; Useful for preparing rule forms and other formats that have repeated boxes and multiple lines. It permits you to duplicate horizontal and vertical placement in relation to the original.
Substrate; The material onto which an image is printed e.g. paper, plastic, metal etc.
TIFF; Tag Image Format File. A document format standard for bit-map graphics (such as paint graphics and scanned images). TIFF files include colour and grey scale information.
Trapping; (1) Digital trap is the controlled overlap of dissimilar adjacent colours to compensate for misregister on the printing press. Previously known as spreads and chokes.
(2) Ink trap or apparent trap is the ability of ink to adhere to wet ink when overprinting.
Trim marks; Short vertical and horizontal lines printed outside the page to indicate the finished page area, and are used by the guillotine operator in the Converting and Finishing area for trimming the excess paper.
Typefaces; A set of characters that share a common design that distinguishes the typeface from all other character sets. It is a Specific letterform design that typically includes all the letters of the alphabet including, numbers and punctuation.
Typography; Setting of type to design and print standards to make type more readable, attractive or outstanding.
Vehicle; With ink manufacturing, that part of the ink that carries the pigment.
Vignette; An illustration in which the background fades gradually away into the unprinted background (sometimes called blends, gradients or fountains). Vignette forms can be horizontal, vertical, radial, etc.
Work and tumble; A process of printing one side of a sheet, then turning the sheet over, retaining the same side lay edges but reversing the gripper edge and using the same printing plate.
Work and Turn; Printing on one side of the paper and then turning it over and printing the other side with the same plate. On the second run, the same gripper edge is maintained but the opposite side lay must be used.
A glossary of terms used on our site