There are nine
main types of printing processes:
- offset lithography printing -
most common type
- thermography -
raised printing, used in stationery
- reprographics -
copying and duplicating
- digital printing -
digital technology is exploding
- letterpress -
the original Guttenberg process
- screen printing -
used for T-shirts, signs and stickers
- flexography -
usually used on packaging, such as boxes
- engraving -
think fine stationery
- gravure -
used for huge runs of magazines and direct-mail catalogs
Offset lithography is the workhorse
of printing. Almost every commercial printer does it. But the quality
of the final product is often due to the guidance, expertise and
equipment provided by the printer.
Offset lithography works on a very
simple principle: ink and water don't mix. Images (words and art)
are put on plates which are dampened first by water, then ink. The
ink adheres to the image area, the water to the non-image area. Then
the image is transferred to a rubber blanket, and from the rubber
blanket to paper. That's why the process is called "offset" --
the image does not go directly to the paper from the plates, as it
does in gravure printing.
