Tuesday, 5 October 2010

What is Print? - At The Printers



Rotary Printing - In this process the image printing plates are wrapped around the cylinder. This is an automated print process and the material to be printed can be sheet fed or on a roll.

The main three types of rotary printing are:

Offset Lithography - Etched aluminum plates wrapped around a cylinder transfer ink to an 'offset' rubber blanket roller and then to the print surface.

High volume runs, newspapers and magazines etc.

Offset means the image is not printed directly onto but offset onto another roller before being

transferred to the substrate to be printed.

This means the image on the plate is the normal way around, reversed when transferred to the middle or’blanket cylinder’ and finally the right way again when on the material to be printed.


The right balance of water and ink is essential to get an even coating of ink on the image plate.


The machine sizes can range from the size of an old mini to the size of 4 double decker busses..and more!










(Litho) Rotogravure (Gravure) - Copper plates (with mirror image) transfer ink directly to print surface, usually on rolls. Advantage is that the plates are more durable and so are good for long print runs.

Rotogravure is similar to offset litho in that the image plate is wrapped around a cylinder.

However the plate itself is made from copper and etched in a different way (intaglio) that gives greater durabality

for longer print runs or tougher substrates. (the material printed on)


Denser ink coverage. Box packaging. Everything dots to hold more ink.

The roller with the Copper etched plate dips into an ink bath and the excess inked scraped

off before the image is transferred directly from the plate to the print substrate from the inked roller.


Typical products that are rotary printed are carton packaging, floorings, laminates, bank notes... large quantity.







Flexography (Flexo) - A positive, mirror image rubber polymer plate, on a cylinder, transfers 'sticky' ink directly to print surface. Usually roll feed. Rubber plates reduce the quality of the print. Used in many high volume food and retail industries. Labels, sweet wrappers, carrier bags and bottles sleeves for example.



Flaxo plates have a rubbery/ silicone feel with the image raised 2-4mm.






Lithography (Litho) PLANOGRAPHIC

Etched aluminium plates on a cylinder transfer ink to an ‘offset’ rubber blanket roller and then to print surface.

Sheet fed or Web fed.

Rotogravure (Gravure) INTAGLIO

Copper plates (with mirror image) transfer ink directly to print surface, usually rolls. Advantage, plates are more durable and so are good for long print runs. Sheet fed or Web fed.

Flexography (Flexo) RELIF

A positive, mirror image rubber polymer plate, on a cylinder, transfer ink directly to print surface. Usually roll feed.



Digital Printing - The reproduction of images by translating the digital code direct from a computer to a material without an intermediate physical process. Short run with materials from paper to metal.

Screen Print - A printmaking technique that uses a woven mesh to support an ink blocking stencil.


Pad Printing - A printing process that can transfer a 2-D onto a 3-D object.



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