Page 146 - Graphic Design and Print Production Fundamentals

134 Chapter 5. Pre-press
negative kerning value should appear in the kerning tool. If no kerning value appears, the font is usually
a poor one and will cause spacing problems in the document it is used in.

Another common problem occurred when combining Adobe Type 1 fonts with TrueType fonts in the
same document. Adobe was the creator of the PostScript programming language, and although it was
easy enough to copy its code and create similar fonts, Adobe has maintained fairly tight control over
licensing the PostScript interpreting engines that determine how the PostScript code is rendered through
a raster image processor. The RIP stores the glyph shapes in a font file in a matrix that can be speedily
accessed when rendering the glyphs. Each glyph is assigned an address in the matrix, and each font
matrix has a unique number assigned to it so that the RIP can assign a unique rendering matrix. Adobe
could keep track of its own font identification numbers but could not control the font IDs that were
assigned to TrueType fonts. If a TrueType font had the same font ID number as the Adobe Type 1 font
used in a document, the RIP would establish the glyph matrix from the first font it processed and use
the same matrix for the other font. So documents were rendered with one font instead of two, and the
glyphs, word spacing, line endings, and page breaks were all affected and rendered incorrectly. For the
most part, this problem has been sorted out with the creation of a central registry for font ID numbers;
however, there are still older TrueType font files out there in the Internet universe that will generate font
ID conflicts in a RIP.

Adobe, Apple, and Microsoft all continued to compete for control of the desktop publishing market
by trying to improve font architectures, and, as a result, many confusing systems evolved and were
discarded when they caused more problems in the RIPs than they solved. There is a common font error
that still causes problems when designers use Adobe Type 1 fonts or TrueType fonts. Most of these fonts
only have eight-bit addressing and so can only contain 256 glyphs. A separate font file is needed to set a
bold or italic version of the typeface. Some page layout programs will allow the designer to apply bold
or italic attributes to the glyphs, and artificially render the bold or italic shapes in the document on the
computer screen. When the document is processed in the RIP, if the font that contains the bold or italic
glyphs is not present, the RIP either does not apply the attribute, or substitutes a default font (usually
Courier) to alert proofreaders that there is a font error in the document. The line endings and page breaks
are affected by the error — and the printing plate, signage, or printout generated becomes garbage at
great expense to the industry.

To solve this problem, Adobe actually cooperated with Microsoft and Apple in the development of a
new font architecture. OpenType fonts have unicode addressing, which allows them to contain thousands
of glyphs. Entire typeface families can be linked together to let designers seamlessly apply multiple
attributes such as condensed bold italic to the typeface, and have the RIP process the document very
closely to what typesetters see on their computer screen. PostScript is also the internal language of most
page layout software, so the same OpenType font files are used to rasterize the glyphs to screen as
the printer’s RIP is using to generate the final output. There can be significant differences in the RIP
software, but many font issues are solved by using OpenType fonts for document creation.

One common font error still persists in the graphic communications industry that acutely underlines
the difference between creating a document on a single user’s computer but processing it through an
imaging manufacturer’s workstation. Designers usually own a specific set of fonts that they use for
all the documents they create. The manufacturer tries to use the exact font file each designer supplies
with the document. The problem once again involves the font ID number, as each font file activated in
an operating system is cached in RAM memory to make the RIP-to-screen process faster. So the font