The number of kern pairs required depends on the style of the typeface and other factors, such as: how the side bearings are apportioned among characters in a typeface, the specific layout design, and the type size. Although each element of pair kern data refers to the separation of a single pair of letterforms or other glyphs in a typeface, the design of pair kern data must take into account the placement of letterforms before and after the pair in question. Therefore, a sequence of letterforms, as assembled into words, and even the amount of spacing between words, must be taken into account when designing kern pair data.

A small number of kern pairs need not be an indication of inferior quality of a font, although it could be. Conversely, a large number of kern pairs (in the thousands) for a general purpose font with a single-byte character set may indicate that the designer did not pay enough attention to optimizing the side bearings of each letterform. Optimizing the side bearings to minimize the number of kern pairs can oftentimes be done if the character collection of the font is to represent a single alphabet, or a related set of alphabets (say, Roman variations) used in languages with words having a similar word formation and spelling (like Indo-European Romance languages). However, if a number of fundamentally different alphabets are drawn from the font (say, Cyrillic, Greek, and Roman variations), or if the groups of languages are fundamentally different (Indo-European Romance, Indo-European Scandanavian, Indo-European Slavic), much less optimization is possible when letterforms are shared. Special purpose fonts (say, for titling or signage) may require a large number of kern pairs for precise, close letterfit. The amount of kern pair data increases (for Roman alphabets) when composite characters are included. Depending on the diacritical mark, the same base character may require different kerning for good typographic representation and letterfit. (This is a compelling reason for the inclusion of composite characters in an encoding.)

It is not unusual that a single typeface, at a given optical size, may be used with many sets of kern pair data. Adjusting kern pair data can impart or alter the emotional impact of a typeface design. It is for this reason that the standardized approach in metrics files of combining pair kern data with other character spacing data may not be the wisest in terms of conserving computer disk storage. Most Production First Software fonts come with no less than 700 kern pairs, and up to 1,300,000 pairs for some Production First Software fonts are available, depending on the type color option and the number of characters and scripts. Deriving kern pair data used to be an art. However, artificial intelligence mathematical and neuro-optical algorithms are now extensively used. Production First Software always uses the human eye to « train » these algorithms for each typeface design.

Pair kerning presented quite a problem in hot type, because either a body had to be morticed (so as to allow proper letterfit) or the pair of characters, already kerned, had to be cast in one body. Morticing was not practical in small point sizes (which necessitated small bodies).

Pair kerning can be implemented either manually (when spacing is individually adjusted between characters) or automatically. Automatic pair kerning is implemented by the application and this is done one of two ways: (1) the application determines pair kern values by an algorithm or looking data up which is built into the program; or (2) obtaining pair kern data directly from the font data. The latter is recommended and preferable because there is more assurance that the letterform designs and the design of the pair kern data work together as intended. There are instances, however, where more than one set of pair kern data for a given typeface is desirable. When the spacing of letterforms is varied (see track kerning), different pair kern data is optimal for close spacing and wide spacing. Closer spacing than normal is usually desired when setting headlines or titles at a large point size. Wider than normal spacing is better when text is set at very small point sizes. Different kern data can also make the same typeface look different. Many advertising agencies use special kerning for this purpose. Production First Software offers a choice of kern data for these reasons in some typefaces.

In mid-2001, Palm bought Be Inc., the developer of probably the most advanced operating system for desktop computers (BeOS) and for Internet appliances (BeIA). How they manage the Be operating systems has yet to be determined at this writing.

The Panose system classifies the typeface design by categorizing aspects of actual overall visual letterform shape, regardless of the historic ancestry of a design. Conversely, other typeface classification schemes, such as the ISO 9541-1 Font Resource Management - Appendix A, classifies the design of typefaces by historic ancestry works according to historic design principles, rather than actual overall visible shape. Production First Software supports ISO9541-1 for Production First Software PostScript fonts using the MatchMaker system.

The first implemented Panose system is called Panose 1.0. A more advanced version, Panose 2.0, which can have variable matching parameters depending on the language script, and handle distortable font technologies such as MultipleMaster and TrueTypeGX, was currently still under development in the late 1990's. Whereas Panose 1.0 was originally developed solely as a typeface matching technology, Panose 2.0 was developed also as a font compression technology.

It consists of <drive letter> : \ <directory name> \ <file name> . <extension> .

The advantages of PDF are that the PostScript syntax is uniform and consistent, no matter how the original PostScript was generated; and it is compressed. The disadvantages include: no support as yet for multibyte text and fonts (which standard PostScript Level 2 allows); extreme difficulty with most types of human modification or even comprehension; and round-trip incompatibility (a possible disadvantage). A round-trip incompatibility can occur if a PDF file is generated from a PostScript file, with a PostScript file generated from an Acrobat reader interpreting the PDF file. If the process is continued, both the PDF and the PostScript files continue to change, thus proving round-trip incompatibility.

There are two subtypes for PDF/X:
PDF/X-1: designed for portable « blind interchange, » with all necessary specification parameters, fonts, and highest-resolution images included in the file; and
PDF/X-2: incomplete file lacking portability, because some specifications, fonts, or images are not included but are supplied at a later stage of the workflow.

PDF/X files are usually made by proprietary commercial utilities designed solely for that purpose.

Phototypositor font glyphs had two features that other cold type technologies rarely have: nicks and traps.

(another definition follows)

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The following planes have already been assigned:

Plane  Plane Name                       Plane Content
 0     Basic Multilingual Plane              living scripts, mathematical and special symbols, 
                                             pi characters, presentation forms
 1     Supplementary Multilingual Plane      dead scripts, ideographic characters #2, 
                                             miscellaneous alphabets, general symbols
 2     Supplementary Ideographic Plane       ideographic characters #3
 14    Supplementary Special Purpose Plane   tag alphabet
 15    Supplementary Private Use Plane #1    private use zone #2
 16    Supplementary Private Use Plane #2    private use zone #3

(another definition follows)

A portable Web site can serve as a marketing tool, a presentation program, and for education. Multimedia (audio and video) and user interaction are often built into a Web site. Supplied on a number of diskettes, a removable hard disk, or a CD-ROM disk, it could be easily loaded on nearly every modern computer system, needing only a Web browser as the reader.

PostScript integrates the handling of general graphics and font resources in a cross-platform manner. It handles graphics and computer data in a uniform, consistent manner across all input/output interfaces (visual, mass storage, and hard copy output). PostScript inherently allows scalability in many processes under its control, such as the resolution with which to display and print graphics, the byte-depth of stored character data, and how information data is managed between computer systems and input/output processes. PostScript as a programming language is brilliantly-conceived in terms of flexibility, utility, and scalability, even though it was originally intended as a machine-generated and managed page description language. Its main limitation for use as a general programming language (which conceivably could be remedied in the future) is that it is an interpreted language. [If one examines the history of established programming languages, most started out as interpreted languages, with compilers added as the use of the language matured.]

While PostScript is a remarkably-crafted first rate technology, its implementation in terms of its inherent capabilities has been, and still is, not fully exploited by Adobe. Marketing strategies aside, PostScript has some useful capabilities (from the viewpoint of the end-user) that have never been widely exploited: specifically, the management of font encoding for single-byte fonts, the availability of Display PostScript on Macintosh and Windows operating systems, and the availability of a software-upgradable PostScript interpreter on a bus card for printers (marketed once by only a few manufacturers).

PostScript initiated a technology/power struggle in late 1990 when Apple and Microsoft introduced a competing font resource format: TrueType. Many feel that this was initiated in part by the desire of Apple and Microsoft to try to capture some of the licensing profit being made by Adobe.

The reason for implementing this is:
(1) A Palm Pilot or PDA has very little memory (as little as 2 Mb);
(2) Downloading data to a Palm Pilot is charged very expensively by 3Com and is usually limited to 150 kB monthly for each account, so that the amount of information downloaded must be kept small; and
(3) A special page designed for a Palm Pilot should be limited in size to 400 b, and is selectable by the PQA.

These rules were specifically designed to maximize visual accessibility for printed materials. Not all of these rules apply to Web pages, and Web pages require additional rules for maximum accessibility capability. For those, see Web accessibility guidelines.

There are two problem in principle with the use of the PUA which have not been resolved as of 2001:
1) Scripts which require special processing to render text (such as writing directions other than left-to-right, a mixture of writing directions on a single page or in a single document, text requiring ligature resolution and substitution, inclusion of interlinear annotation, complex scripts, or scripts which have not been introduced into the Unicode standard) have no way currently of relating to PUA character properties to determine what kind of special processing is necessary. Since the idea of the PUA is a « free-for-all, » any type of character belonging to any script may be included in the PUA. Since the PUA can also vary font by font, the character properties must be identified on two levels: at the text level (so as to agree on how to represent PUA characters in the actual text), and at the font level (so as to be able to identify the nature of the characters which can be represented by glyphs in the font).
2) Since the nature of PUA characters which can be serviced by fonts can vary from font to font, identifying PUA characters on a plaintext level may be moot, a rich text format level being required to identify fonts in text.

A third system of color reproduction is the Land method (discovered by Dr. Edwin H. Land, inventor of the Polaroid camera system), which can be considered to use a monochrome image and one process color which is formulated to work along with the color correction attribute built into the human eye and brain.

In terms of human color visual limits, the additive three color system (RGB) is theoretically the most accurate, followed by HiFi color (using 6 to 8 process colors), four process colors (CMYK), two additive colors (yellow-green, magenta), three process colors (CMY), and the Land method. In terms of practical technology and reproducibility, the HiFi color method is the most accurate.

The first usage of push technology was to install application and operating system software onto a client from a server. Currently, push technology is also being utilized as a sort of computer data broadcasting technique, where information (mostly advertising) is transmitted from a server over the Internet to a client asynchronously and without demand. The client must be connected to the Internet for this to occur.

The disadvantages of push technology are that it hogs bandwidth and represents an Internet security risk.

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