Print Technology

Print technology begins with the earliest printing presses, which used wooden, and later metal, letter forms to press ink onto paper. Modern printing technologies include:

1. Offset lithography: Books, magazines, and newspapers are usually printed with this method. Traditionally, an inked image is transferred from a plate first to a rubber blanket, then to the printing surface, usually paper. A photographic negative process is used to create a reverse image on a paper or plastic 'plate.' This plate is then attached to the plate roller on the printing press, which then presses the ink onto the paper.
2. Computer to Film: From desktop publishing programs a digital graphic art file is created and then output onto a transparent film, which is then used to create a negative printing plate.
3. Computer to Plate: Offset presses increasingly use computer to plate systems which create a complete digital work flow process.
4. Flexography: Most often used for packaging - achieved by creating a mirrored master of the image as a 3D relief in a rubber or polymer material. This has the advantage of flexibility in adhering ink to uneven surfaces such as cardboard or other packaging materials.
5. Rotogravure: Engraves the image onto an image carrier, such as a copper cylinder used on a rotary printing press, usually fed with rolls of paper rather than individual sheets. Gravure cylinders are typically engraved digitally by a diamond tipped or laser etching machine. The engraved image is composed of small recessed dots (wells) that hold ink. The depth and size of these dots control the amount of ink that gets transferred to the material - usually paper, plastic or foil - with a process of pressure, osmosis, and electrostatic pull.
6. Thermal Ink Jet: Most consumer inkjet printers use a print cartridge with tiny electrically-heated chambers. To produce an image, the printer runs a pulse of current through the heating elements. A steam explosion in the chamber forms a bubble, which propels a droplet of ink onto the substrate surface.
7. Piezoelectric Ink Jet: Most commercial inkjet printers use piezoelectric crystals in each spray nozzle. When current is applied, the crystal bends, forcing a droplet of ink from the nozzle, which is sprayed on the substrate surface.
8. Laser: Image are produced by the direct scanning of a laser beam across the printer's internal drum. •