Print, a list of things I now understand.

So, the main four types of printing are:
- Rotary Printing, which includes Offset Lithography, Flexography and Rotogravure.
- Digital Printing, which is pretty straight forward anyway. It's digital, like in the digital print resource.
- Screen Printing, which uses screens to print from by layering inks and is often used for t-shirts and stuff.
- Pad Printing, which takes ink from a plate and transfers it to a pad which then can be transferred to a variety of substrates either 2 or 3D.

Lithography
The inked image from a printing plate is transferred or offset on to a rubber blanket roller, which is then pressed against the stock or substrate. Litho plates are smooth and works on the basis that oil repels water. When the plate passes under the ink roller, non-image areas that have a water film repel the inks which stick to image areas.

Litho seems to be the most commonly used process because plates are easy to prepare and the cost of printing is relatively low. Litho printers can either be sheet fed or have a continous web feed. Sheet-fed would be used for a small print jobs including flyers and brochures, where as web-fed presses would be used for newspapers, magazines and reports because of the high volume.

The downside to litho printing is that the plates are less durable compared to relief printing like flexo and gravure.

One thing I did not realise before was that printing plates C, M, Y, K, although they are printed in this order, the order can be changed to achieve a different effect, sometimes this can be undesirable or improve a print if the printer feels the order of plates could be changed, but this becomes more relevant when printing using spot colours.


Rotogravure is a common commercial relief printing process in which an image is engraved into a copper printing plate (thats why the plates are so durable) and is pressed directly against the substrate. Small cells are are engraved into the plate that hold the ink ready to be transferred to the stock. It is a high speed print process that delivers a high volume of production and has the widest print presses. It is used for massive print runs.

Flexography is printed using the surface differences in the plate. The process creates a rubber relief of the image, which is inked and pressed against the substrate. It was developed for printing packaging and traditionally gave poor results but now it competes with the likes of rotogravure and lithography, particularly as it can print a wide range of substrates due to the flexibility of the plate. It is often used for medium to large sized print runs.

Rotogravure and flexo print processes uses lower viscosity inks than litho so the drying time is much faster.


Screen Printing is a low volume print method, which involves viscous inks passing through a screen that holds a design, onto a substrate. Although it is a relatively slow and low-volume and expensive printing method, this print process can be used to print onto a variety of substrates, including cloth, ceramics, and metals.




This is a screen printed design for Levi's by Kate Gibb and Rob Petrie. It features a tritone finish. I love the edgyness to this style of print, its like photocopying with colour. It reminds me of a fashion designers sketch.









Pad printing is a printing process that can transfer a 2-D image onto a 3-D object. This is accomplished using an indirect offset gravure printing process that involves an image being transferred from the printing plate (cliché) via a silicone pad onto a substrate (surface to be printed). Pad printing is used for printing on otherwise impossible products in many industries including medical, automotive, promotional, apparel, electronics, appliances, sports equipment and toys. It can also be used to deposit functional materials such as Conductive ink, adhesives, dyes and lubricants.