Glossary of Terms

Banding

Visible lines or stripes of differing density on a printed inkjet image, considered as a fault. It's always associated with scanning-carriage inkjets and appears across the print width. If the print is intended for viewing from a distance, such as a billboard, banding may not be a problem as it is hardly visible.

Bézier curves

These are mathematical descriptions of curves that are commonly used for vector drawing, with a graphical user interface that allows the user to create and modify them. On-screen the designer sees them as arcs linked by anchor points with extendable handles that are used to alter the shape to any extent.

Binary Inkjet

A drop-on-demand printhead which can either fire a drop of one particular size or no drop at all (binary being on or off with no in-between). This contrasts with greyscale heads, that can fire several different droplet sizes to give different ink densities. See Greyscale.

Bit

Binary Digit. Computers work with numbers built up from just two states: 0 or 1, equivalent to an electrical switch being off or on. They are normally grouped together in eights, called bytes. An 8-bit byte can contain any number between 0 and 255. See Byte.

Bit depth

Each pixel in a digital image can be assigned a particular shade, or grey level, between white and black. This is represented in a computer by a binary number, ie a string of 0 and 1 numbers.

Bitmap

Technical description for the way a computer builds up an image from building blocks of dots, or pixels. An image on a screen is a bitmap. A processed image that is output by a raster image processor (RIP) to a printer or imagesetter is a bitmap.

Byte

A block of bits, normally a group of eight. Using binary numerals, an 8-bit byte can be used to count from 0-255, giving 256 values. This figure appears frequently in graphic arts, as it is often used as the number of density levels per colour that a computer screen or halftone dot is capable of reproducing.