Lorenzo print seminar - at the printers

Commercial printing processes are:
>practical
>technical
>economical

Processes include 
-rotary printing
-digital printing
-screen printing
-pad printing

Knowing print processes helps avoid nasty surprises when you get your work back from the printers. 

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

The 3 main types of rotary printing are :
Offset Lithography (Litho)
Rotogravure (Gravure)
Flexography (Flexo)

Offset lithography
A process using etched aluminium plates wrapped around a cylinder that transfer ink to an ‘offset’ rubber blanket roller and then to the print surface. Sheet fed or Web fed.

Most web machines are incredibly high speed and run ‘rolls’ of material as opposed to sheet fed. Often have finishing and folding built into the machine.

Rotogravure
Copper plates (with mirror image) transfer ink directly to the print surface, usually on rolls. An advantage of this process is that the plates are more durable and so are good for long print runs.

Typical Gravure print jobs are high volume, durable.

Flexography 
A positive, mirror image rubber polymer plate, on a cylinder, transfers ‘sticky’ ink directly to print surface. Usually roll feed.

Typical flexo print jobs are high volume, low quality. Often these are throw away goods like bottle labels and such, that isn't likely to be kept.


• Lithography (Litho) PLANOGRAPHIC Etched aluminium plates on a cylinder transfer ink to an ‘offset’ rubber
blanket roller and then to print surface.
• 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.
• Flexography (Flexo) RELIEF
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.


> digital print is ideally suited to short or special print runs on a range of media from paper to metal.


Screen Printing
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 image onto a 3-D object.