Digital printing Digital printing involves printing directly from a digital file. Digital has a higher cost per page than litho offset printing but doesn't have the costs of plate making and machine set-up involved in litho printing. Digital is therefore ideal for short run books containing mono and/or colour pages: up to around 750 copies, it is often more economical than litho printing.
For mono book pages we use HP high volume laser based printers and Lexmark and Xerox high volume laser printers for colour pages. For book covers and digital art prints we use an HP Indigo press.
Litho printing (short for lithographic) is an offset printing technique based on the repulsion of oil and water, the printing plate carrying the image area to be printed takes the ink from the ink rollers of the press and transfers it to the paper while the non-printing area remains ink-free.
For book work we use a fully automated 8-colour Komori Lithrone S840P with maximum printing size of 720mm x 1003mm and a reversible 2-colour Komori Lithrone 40 with maximum printing size of 720mm x 1003 mm. The S840P is a perfecting press: i.e. it is able to print four colours on both sides of a sheet in the same pass through the press or can be used to add extra colours, such as specials or metallics, or coating to normal four-colour jobs; resulting in quicker printing, less machine time and a substantial reduceduction in registration errors.
Metallic inks can be particularly useful in differentiating a book cover from others on the bookshelf. Metallic inks are special inks with fine reflective metallic particles that create a shine and luster that that cannot beachived with standard inks. Silver and gold metallics are most common, but metallic inks also come in bright blues, vibrant purples, hot reds and burnished coppers
Hot foil stamping is an alternative to printing with a metallic ink and provides a a bright, shiny, dense, metallic surface that is ideal for enhancing the attractiveness of book covers. In hot foil stamping, a metal die in which the printing surface is raised above the non-printing surface is used in a letterpress. The die transfers the foil to the paper as the press operates and a combination of heat and pressure adheres the foil to the paper. There are a wide variety of effects to choose from, including gold, silver, colored metallics and marble.
Varnishing (also known as coating or sealing) involves applying a liquid coating to the printed sheets to add a clear glossy, matte, satin, or neutral finish. Varnishing can be carried out on the press and serves to increases colour absorption and speeds up the drying process. The varnish also fixes the ink under its protective coat to prevent the ink rubbing off when the paper is subjected to handling.
UV (ultraviolet) varnishing involves the application of a coating that requires special ultraviolet drying machinery. A UV varnish provides a more noticeable effect and can be applied to the whole printed surface (all-over UV varnish) or to selected elements (spot UV varnish). A UV varnish can be used to enhance the attractiveness of a printed book. A spot varnish can be used to enhance the attractiveness of a printed book by drawing attention to a specific part of a page, providing an additional visual stimulus which can add interest and identifies a particular book as a premium product.