Printer
Languages:
Printer
languages are commands from the computer to the printer to tell the printer how
to format the document being printed. These commands manage font size,
graphics, compression of data sent to the printer, color, etc. The two most
popular printer languages are Postscript and Printer Control Language.
Postscript
is a printer language that uses English phrases and programmatic constructions
to describe the appearance of a printed page to the printer. This printer
language was developed by Adobe in 1985. It introduced new features such as
outline fonts and vector graphics. Printers now come from the factory
with or can be loaded with Postscript support. Postscript is not restricted to
printers. It can be used with any device that creates an image using dots such
as screen displays, slide recorders, and image setters.
PCL
(Printer Command Language) is an escape code language used to send commands to
the printer for printing documents. Escape code language is so-called because
the escape key begins the command sequence followed by a series of code
numbers. Hewlett Packard originally devised PCL for dot matrix and inkjet
printers. Since its introduction, it has become an industry standard. Other
manufacturers who sell HP clones have copied it. Some of these clones are very
good, but there are small differences in the way they print a page compared to
real HP printers. In 1984, the original HP Laserjet printer was introduced using
PCL. PCL helped change the appearance of low-cost printer documents from poor
to exceptional quality.
Fonts:
A font
is a set of characters of a specific style and size within an overall typeface
design. Printers use resident fonts and soft fonts to print documents. Resident
fonts are built into the hardware of a printer. They are also called internal
fonts or built-in fonts. All printers come with one or more resident fonts.
Additional fonts can be added by inserting a font cartridge into the printer or
installing soft fonts to the hard drive. Resident fonts cannot be erased unlike
soft fonts. Soft fonts are installed onto the hard drive and then sent to the
computer's memory when a document is printed that uses the particular soft
font. Soft fonts can be purchased in stores or downloaded from the Internet.
There are
two types of fonts used by the printer and screen display, bitmap fonts
and outline fonts. Bitmap fonts are digital representations of fonts that are
not scalable. This means they have a set size or a limited set of sizes. For
example, if a document using a bitmap font sized to 24 point is sent to the
printer and there is not a bitmap font of that size, the computer will try to
guess the right size. This results in the text looking stretched-out or
squashed. Jagged edges are also a problem with bitmap fonts. Outline fonts are
mathematical descriptions of the font that are sent to the printer. The printer
then rasterizes or converts them to the dots that are printed on the paper.
Because they are mathematical, they are scalable. This means the size of
the font can be changed without losing the sharpness or resolution of
the printed text. TrueType and Type 1 fonts are outline fonts. Outline
fonts are used with Postscript and PCL printer languages.
No comments:
Post a Comment