Introduction to Printing

We have recently been learning theory regarding printing.

Three of the main printing types we learnt about were Offset, Screen and Inkjet Printing.

Offset Printing utilises multiples rollers that use the repulsion of oil and water in combination with ink to offset/transfer an inked image onto a rubber blanket and then onto the paper. This paper travels through multiple sets of rollers, with each set being either Cyan, Magenta, Yellow or Black (CMYK). This is otherwise known as Lithographic Printing, especially when the oil and water repulsion technique is employed. Once the paper has received all of the colour/ink information it is cooled via cold and warm air.Image result for offset printing process1*

Screen Printing is when ink or metal is forced onto a surfaced through a prepared screen/mesh made from fine material to create a picture or pattern (e.g. screen-printed clothing). A blade is used to fill the mesh with ink and then a reverse stroke causes the substrate to be momentarily touched by the screen along a line of contact. The ink wets the substrate and is then pulled out of the mesh as the screen moves back to how it was after the blade has passed. The frame used for Screen Printing is usually made from wood.Image result for screen printing process2*

 

The emulsion exposure times for the screens are usually 4-15 minutes and varies per bulb.

Inkjet Printing uses drops of ink to recreate digital images onto a surface, almost like a screen’s pixel information.

A bleed of 3-5mm is usually used and text must be 3mm from the bleed.

 

(Images found online)

Sources for images:

1*: http://blog.thepapermillstore.com/digital-press-papers/

2*: http://www.bbc.co.uk/schools/gcsebitesize/design/graphics/mechanismfinishprintrev1.shtml