Modern printing technology

Books and newspapers are printed today using the technique of offset lithography. Other common techniques include

• flexography used for packaging, labels, newspapers
• screen printing from T-shirts to floor tiles
• rotogravure mainly used for magazines and packaging,
• inkjet used typically to print a small number of books or packaging, and also to print a variety of materials from high quality papers simulate offset printing, to floor tiles; Inkjet is also used to apply mailing addresses to direct mail pieces
• Hot Stamping Printing.
• laser printing mainly used in offices and for transactional printing (bills, bank documents). Laser printing is commonly used by direct mail companies to create variable data letters or coupons, for example.

Gravure

For this process, the image to be printed is made up of small holes sunk into the surface of the printing plate. The cells are filled with ink and the excess is scraped off the surface, then a rubber-covered roller presses paper onto the surface of the plate and into contact with the ink in the cells. The printing plates are usually made from copper and may be produced by engraving or etching.

Gravure printing is used for long, high-quality print runs such as magazines, mail-order catalogues, packaging, and printing onto fabric and wallpaper. It is also used for printing postage stamps and decorative plastic laminates, such as kitchen worktops.

Digital Printing

Printing at home or in an office or engineering environment is subdivided into:

• small format (up to ledger size paper sheets), as used in business offices and libraries
• wide format (up to 3' or 914mm wide rolls of paper), as used in drafting and design establishments.

Some of the more common printing technologies are

• line printing — where pre-formed characters are applied to the paper by lines
• daisy wheel — where pre-formed characters are applied individually
• dot-matrix — which produces arbitrary patterns of dots with an array of printing studs
• heat transfer — like early fax machines or modern receipt printers that apply heat to special paper, which turns black to form the printed image
• blueprint — and related chemical technologies
• inkjet — including bubble-jet — where ink is sprayed onto the paper to create the desired image
• laser — where toner consisting primarily of polymer with pigment of the desired colours is melted and applied directly to the paper to create the desired image.