Digital printing is a method of printing from a digital-based image directly to a variety of media. It usually refers to professional printing where small-run jobs from desktop publishing and other digital sources are printed using large-format and/or high-volume laser or inkjet printers.
Digital printing has a higher cost per page than more traditional offset printing methods, but this price is usually offset by avoiding the technical steps required to make printing plates. It also allows for on-demand printing, short turnaround time, and even a modification of the image (variable data) used for each impression. The savings in labor and the ever-increasing capability of digital presses means that digital printing is reaching the point where it can match or supersede offset printing technology's ability to produce larger print runs of several thousand sheets at a low price.
Process
thumb|left|Large format digital prints
The greatest difference between digital printing and analog methods, such as lithography, flexography, gravure, and letterpress, is that in digital printing (introduced in the 1980s) there is no need to replace the printing plate, whereas in analog printing the plates are repeatedly replaced. This results in quicker turnaround time and lower cost in digital printing, but typically a loss of detail in most commercial digital printing processes. The most popular methods include inkjet and laser printers, which deposit pigment and toner, respectively, onto substrates, such as paper, canvas, glass, metal, and marble.
In many of the processes, the ink or toner does not permeate the substrate, as does conventional ink, but forms a thin layer on the surface that may be additionally adhered to the substrate by a fuser fluid with thermal (toner) or ultraviolet curing (ink).
Digital printing methods of note
Fine art inkjet printing
thumb|left|Large format printing of black numbers on a brushed aluminum sheet by a Mimaki inkjet printer
Fine art digital inkjet printing is printing from a computer image file directly to an inkjet printer as a final output. It evolved from digital proofing technology developed by Kodak, 3M, and other major manufacturers, with artists and other printers trying to adapt these dedicated prepress proofing machines for fine-art printing. There was experimentation with many of these types of printers, the most notable being the IRIS printer, initially adapted to fine-art printing by programmer David Coons, and adopted for fine-art work by Graham Nash at his Nash Editions printing company in 1991. Initially, these printers were limited to glossy papers, but the IRIS Graphics printer allowed the use of a variety of papers that included traditional and non-traditional media. The IRIS printer was the standard for fine art digital printmaking for many years, and is still in use today, but has been superseded by large-format printers from other manufacturers such as Epson and HP that use fade-resistant, archival inks (pigment-based, as well as newer solvent-based inks), and archival substrates specifically designed for fine-art printing.
Substrates in fine art inkjet printmaking include traditional fine-art papers such as Rives BFK, Arches watercolor paper, treated and untreated canvas, experimental substrates (such as metal and plastic), and fabric.
thumb|left|Digital Printing Press
For artists making reproductions of their original work, inkjet printing is more expensive on a per-print basis than the traditional four-color offset lithography, but with inkjet printing, the artist does not have to pay for the expensive printing-plate setup or the marketing and storage needed for large four-color offset print runs. Inkjet reproductions can be printed and sold individually as demand dictates. Inkjet printing has the added advantage of allowing artists to take total control over the production of their images, including final color correction and the substrates used, with some artists owning and operating their own printers.
Digital inkjet printing also allows the output of digital art in all forms, as finished pieces or as elements in a further art piece. Experimental artists often add texture or other media to the surface of a final print or use it as part of a mixed-media work. Many terms for the process have been used over the years, including "digigraph" and "giclée". Thousands of print shops and digital printmakers now offer services to painters, photographers, and digital artists worldwide.
Digital images are exposed onto true, light sensitive photographic paper with lasers and processed in photographic developers and fixers. These prints are true photographs and have continuous tone in the image detail. The archival quality of the print is as high as the manufacturer's rating for any given photo paper used. In large format prints, the greatest advantage is that, since no lens is used, there is no vignetting or corner detail distortion.
Digital cylinder printing
Digital cylinder printing is when a machine directly lays ink onto a curved surface, usually the wall of an object with a circular cross-section and a constant, tapered, or variable diameter. Digital cylinder printing is a method of reproducing black-and-white or full-color images and text onto cylindrical objects, typically promotional products, using digital imaging systems.
The digital process is, by definition, faster than conventional screen printing, because it requires fewer production steps and less setup time for multiple colors and more complex jobs. This, in turn, enables reduced run lengths.