Some of technical printing terms explained.
Against the grain
At right angles to the grain direction to the paper.
Bitmap
A grid of pixels or printed dots generated by computer to represent type and images.
Bleed
The printed image extends beyond the trim edge of a sheet or page.
Crop Marks
Special lines near the margins of artwork indicating where to trim, perforate of fold.
Creep
Phenomenon when middle pages of a folded section extend slightly beyond the outside pages.
Clipping path
An outline, embedded into the file, that tells an application which areas of a picture should be considered transparent.
Dot gain
A printing defect in which dots print larger than intended, causing darker colour or tones, due to the spreading of ink on stock, the more absorbent the stock, the more dot gain.
DPI
A measure of the quality of an image from a scanner or output resolution of a printer, the more dots per inch, the higher the quality will be.
Embed
Implies the inclusion of elements and data into a computer file necessary to maintain or change the elements when used remotely.
Font
One of a range of styles/typefaces in which lettering can be produced during the typesetting stage.
Gutter
Line or fold at which facing pages meet.
Greyscale
Shades of grey ranging from black to white, in printing, greyscale uses only a black halftone plate.
Hickey
Spot or imperfection in printing.
Import
To bring a picture of text file into an application ready for editing or design work.
Kerning
The adjustment of spacing between certain letter pairs, A and V for example, to obtain a more pleasing appearance.
lpi
Lines per inch – refers to the quality of a halftone screen.
Make-ready
The work associated with the set-up of printing equipment before running a job.
Outline paths
A term used when converting a font or graphic into a mathematical vector format, can also be called curves.
Point
A measurement for the size of type, distance between lines and thickness of rules, one point equals one seventy-second of an inch (0.3515mm).
Proof
A representation of the finished print digitally produced for customer inspection for any errors or omissions.
Registration Marks
Crosses or other marks placed on artwork which ensure perfect alignment.
Reversed out
Type appearing white on a black or colour background, either a solid or a tint.
Resolution
The number of dots per inch (dpi) in a computer process document, the level of detail retained by a printed document increases with higher resolution pixels per inch for an image.
RIP (Raster Image Processor)
Computer using specialist software to convert document based information into bitmap information required by output devices.
Rosette
The formation created by the dots that make up four colour images. The dots in magenta, cyan, yellow and black overlap each other in a cluster, because the dots are not perfectly round and because they are turned at angles to each other, this cluster resembles the arrangement of petals in a rose.
Solid
An area on the page which is completely covered by the ink.
Tint
An area of tone made by a pattern of dots, which lightens the apparent colour of the ink with which it is printed.
Trapping
A slight overlapping between the two touching colours that prevents gaps from appearing along the edges of an object because of misalignment or movement on the printing press.