Print Seminar 1

The four types of printing are:

• Rotary
• Digital
• Screen
• Pad

Rotary

Image printing plates are wrapped around a cylinder and can be printed on various substrates which can then be further modified if required. The 3 main types of rotary printing are:

1) Offset lithography (planography)

An inked image is transferred or 'offset' from an etched aluminium plate, to a rubber blanket and then to the print surface. The planographic image carrier (plate) obtains ink from the ink rollers where the image is while the non-printing areas attracts a water-based film keeping these ink-free.

2) Gravure (Intaglio)

Copper plate transfer ink directly to the print surface, usually on rolls. They are the fastest and more durable of all the printing processes therefore are usually used for high volume products. Photo gravure is high quality but expensive.

3) Felxography (Relief)

A positive, mirror image rubber polymer plate on a cylinder, transfers 'sticky ink' directly onto the print surface. It can be used for printing on almost any type of substrate including plastic, cellophane and paper. Examples of products are crisp packets and bottle labels.

Digital printing

Direct from a computer to a material without an intermdiate physical process and is ideally suited for short runs (longer runs use the more traditional printing methods). An advised process would be:

1) Test print - Inspect colours, spelling, spacing and size

2) Refinement - Another mock up

3) Choose which stock you wish to use

Screen printing

It uses a woven mesh to support an ink blocking stencil. A roller or squeegee is moved across the screen, forcing the ink through the open areas and onto the substrate. This is then repeated if necessary to achieve multiple colours.

Inspecting prints