Digital Printing - What is digital printing?
Any method of printing that processes images in a digital format (rather than an analogue format). The term “digital” refers to data or information that is generated, stored, or processed in a discrete (discontinuous) numerical form; digital files are made up of a series of digits (either 1 or 0) and are transmitted as being in one of two states (e.g. 1 or 0, on or off, positive or negative, true or false, black or white). These digits are known as “binary digits” or “bits”.
As digital printing can only process images in the form of a digital file, these processes usually begin with a conversion stage, whereby the image is converted into a digital file that can be processed by the printer or press being used. This usually involves a Raster Image Processor (either in a piece of software or as a component of a printer or press) converting the image being printed into a raster image or “bitmap”. A bitmap is a rectangular grid of pixels, which are “points of colour”; each pixel is made up of a number of bits, with each bit representing one of two distinct colours. The number of bits per pixel determines the number of distinct colours (and therefore the depth of colour) that a single pixel can represent. The bitmap is then sent for output, where the printer or press will create the image as a dot matrix pattern based on the bitmap. While the resolution of the bitmap is expressed in pixels per inch (ppi), the resolution of a printer is expressed as dots per inch (dpi), and each pixel in the bitmap is represented by a multitude of dots on the printed substrate.
Where analogue printing creates multiple copies from one fixed original image, digital printing involves the creation of a new image for every print that is produced; this means that digital printers are capable of variable information printing, where each print can vary slightly from one to the next. For example, a set of invitations could be printed with the same design but personalised with the name of each intended recipient.
It should be noted that, while most digital printing involves digital files from start to finish, the process can begin with an analogue image, such as a photograph that has been developed from photographic film or a design or piece of artwork that has been created by hand. In these cases, the analogue image will be scanned and converted into a digital image, which can then be processed by a digital printer or press.
Digital printing refers to a range of modern printing methods, such as direct thermal printing, dot matrix printing, electrostatic printing, inkjet printing, ion deposition printing, laser printing, and thermal transfer printing.Go Back to Glossary