One of the greatet technological advancements in the last 50 years has been the development of printers. Printing has changed the pace at which we can communicate which means ideas, products and services can be marketed quicker than ever. There are many forms of printing which have cropped up over the years, some are now obsolete, others are still used for niche areas, and some such as digital printing are just taking off!
Digital printing Is the reproduction of digital images on a physical surface. It is generally used for low quantity print runs, and for the customization of print media. When used correctly digital printing can greatly impact an overall communication campaign. It can be differentiated from litho, flexography, gravure or letterpress printing in many ways, some of which are;
Every printed impression made onto the paper can be different, as opposed to making several hundred or thousand impressions of the same image from one set of printing plates, as in traditional methods. It requires less waste in terms of chemicals used and paper wasted in set up (bringing the image "up to colour" and checking registration or position). The Ink or Toner does not absorb into the substrate, as does conventional ink, but forms a thin layer on the surface and may in some systems be additionally adhered to the substrate by using a fuser fluid with heat process (toner) or UV curing process (ink). Because of the lack of a need to make plates or run up to colour, it is useful for rapid prototyping, and cost effective for small leaflet or business card print runs.
Gravure Printing With gravure printing an image is etched on the surface of a metal plate, the etched area is filled with ink, then the plate is rotated on a cylinder that transfers the image to the paper or other material.
Intaglio Printing Invented in Germany by the 1430s, Intaglio Prinitng is a family of printmaking techniques in which the image is incised into a surface, known as the matrix or plate. Normally, copper or zinc plates are used as a surface, and incisions are created. To print an intaglio plate ink is applied to the surface and then rubbed with tarlatan cloth to remove most of the excess leaving ink only in the incisions. A damp piece of paper is placed on top and the plate and paper are run through a printing press that, through pressure, transfers the ink from the recesses of the plate to the paper.
Litho Printing The litho printing process can print 4 to 5 colours at one time and extra colours such as gold or silver can be added too. Litho printing is fast, efficient and good value for money. For most printing projects itâ€™s the perfect solution. Litho printing is also known as lithography or lithographic printing or planography or planographic printing. Litho printing works on the basic principle that oil and water do not mix. Unlike relief printing and intaglio where the image and non-image areas are at different levels, in lithography there is only one surface. Litho printing is best for print runs over 1000, such as mass leaflet marketing campaigns; anything under this would be more cost effective to be printed by the digital printing process.
Offset printing Offset printing is a commonly used printing technique where the inked image is transferred (or "offset") from a plate to a rubber blanket, then to the printing surface. When used in combination with the lithographic process, which is based on the repulsion of oil and water, the offset technique employs a flat (planographic) image carrier on which the image to be printed obtains ink from ink rollers, while the non-printing area attracts a water-based film (called "fountain solution"), keeping the non-printing areas ink-free.
Advantages of offset printing compared to other printing methods include a consistent high image quality. Offset printing produces sharp and clean images and type more easily than letterpress printing because the rubber blanket conforms to the texture of the printing surface. Quick and easy production of printing plates. Longer printing plate life than on direct litho presses because there is no direct contact between the plate and the printing surface. Properly developed plates running in conjunction with optimized inks and fountain solution may exceed run lengths of a million impressions. The more you print, the less you pay per page, because most of the price goes into the preparation undergone before the first sheet of paper is printing and ready for distribution. Any additional paper print will only cost the client paper price (and ink), which is very minimal.
Disadvantages of offset printing compared to other printing methods include a slightly inferior image quality compared to rotogravure or photogravure printing and propensity for anodized aluminum printing plates to become sensitive (due to chemical oxidation) and print in non-image/background areas when developed plates are not cared for properly.
Photogravure Printing Registers an extraordinary variety of tones, through the transfer of etching ink from an etched copperplate to special dampened paper run through an etching press. The unique tonal range comes from photogravure's variable depth of etch, that is, the shadows are etched many times deeper than the highlights. Unlike half-tone processes which merely vary the size of dots, the actual quantity and depth of ink wells are varied in a photogravure plate and are often blended into a smooth tone by the printing process. Photogravure continues to be used for very fine printing.
Relief Printing A relief print is an image created by a printmaking process, such as woodcut, where the areas of the matrix (plate or block) that are to show printed black (typically) are on the original surface; the parts of the matrix that are to be blank (white) having been cut away, or otherwise removed. Printing the image is therefore a relatively simple matter of inking the face of the matrix and bringing it in firm contact with the paper; a printing-press may not be needed as the back of the paper can be rubbed or pressed by hand with a simple tool. Rubber stamps are an example of this kind of printing.
Rotogravure Printing Roto or gravure for short is a type of intaglio printing process, in that it involves engraving the image onto an image carrier. In gravure printing, the image is engraved onto a copper cylinder because, like offset and flexography, it uses a rotary printing press. The vast majority of gravure presses print on reels of paper, rather than sheets of paper. (Sheetfed gravure is a small, specialty market.) Rotary gravure presses are the fastest and widest presses in operation, printing everything from narrow labels to 12-feet-wide rolls of vinyl flooring. Additional operations may be in-line with a gravure press, such as saddle stitching facilities for magazine/brochure work. The rotogravure process is still used for commercial printing of magazines, postcards, and corrugated (cardboard) product packaging.
Please add anymore printing methods which you may know of!
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