PostScript fonts are font files encoded in outline font specifications developed by Adobe for professional digital typesetting. This system uses the PostScript file format to encode font information.
PostScript fonts may also separately be used to refer to a basic set of fonts included as standards in the PostScript system, such as Times New Roman, Helvetica, and Avant Garde.
History Type 1 and Type 3 fonts, though introduced by Adobe in 1984 as part of the PostScript page description language, did not see widespread use until March 1985, when the first laser printer to use the PostScript language, the Apple LaserWriter, was introduced.
Even then, in 1985, the outline fonts were resident only in the printer, and the screen used bitmap fonts as substitutes for outline fonts.
Although originally part of PostScript, Type 1 fonts used a simplified set of drawing operations compared to ordinary PostScript (programmatic elements such as loops and variables were removed, much like PDF), but Type 1 fonts added hints to help low-resolution rendering. Originally, Adobe kept the details of their hinting scheme undisclosed and used a (simple) encryption scheme to protect Type 1 outlines and hints, which still persists today (although the encryption scheme and key have since been published by Adobe). Despite these measures, Adobe's scheme was quickly reverse-engineered by other players in the industry. Adobe nevertheless required anyone working with Type 1 fonts to license their technology.
Type 3 fonts allowed for all the sophistication of the PostScript language, but without the standardized approach to hinting (though some companies, such as ATF, implemented their own proprietary schemes) or an encryption scheme. Other differences further added to the confusion.
The cost of the licensing was considered very high at this time, and Adobe continued to stonewall on more attractive rates. It was this issue that led Apple to design their own system, TrueType, around 1991. Immediately following the announcement of TrueType, Adobe published ”Adobe type 1 font format”, a detailed specification for the format. Font development tools such as Fontographer added the ability to create Type 1 fonts. The Type 2 format has since been used as one basis for the modern OpenType Format.
Technology In the PostScript (PS) language glyphs are described with cubic Bézier curves (as opposed to the quadratic curves of TrueType), and thus a single set of glyphs can be resized through simple mathematical transformations performed in a PostScript raster image processor such as in a PostScript printer. Because the data of Type1 is a description of the outline of a glyph and not a raster image (i.e. a bitmap), Type1 fonts are commonly referred to as outline fonts as opposed to bitmap, or screen, fonts. Bitmap versions of outline fonts were used on-screen, but bitmap fonts aligned with the pixels of screens, not the higher-resolution grids of printers and imagesetters, causing differences in letter spacing, line wraps, and other copy-fitting issues. Print dialogs included an option to mitigate this discrepancy by printing at 96% size, fitting each screen pixel to an integral number of print pixels. The alternative was Adobe Type Manager, which rendered PostScript fonts on-screen, using hinting and, on color and greyscale screens, providing anti-aliasing, which, aside from smoothing the edges of glyphs on-screen, allowed on-screen letter spacing matching print output to not appear as irregular.
Font type
Type 0 Type 0 is a composite font format—as described in the PostScript Language Reference Manual, 2nd Edition. A composite font is composed of a high-level font that references multiple descendant fonts.
Type 1
Type 1 (also known as PostScript, PostScript Type 1, PS1, T1 or Adobe Type 1) is the font format for single-byte digital fonts for use with Adobe Type Manager software and with PostScript printers. It can support font hinting.
It was originally a proprietary specification, but Adobe released the specification to third-party font manufacturers provided that all Type 1 fonts adhere to it.
Type 1 fonts are natively supported in macOS, and in Windows 2000 and later via the GDI API. (They are not supported in the Windows GDI+, WPF or DirectWrite APIs.)
Adobe announced on 27 January 2021 that they would end support for Type 1 fonts in Adobe products after January 2023. Support for Type 1 fonts in Adobe Photoshop was discontinued with the release of version 23.0 of the product in October 2021.
Type 2 Type 2 is a character string format that offers a compact representation of the character description procedures in an outline font file. The format is designed to be used with the Compact Font Format (CFF). The CFF/Type2 format is the basis for Type 1 OpenType fonts, and is used for embedding fonts in Acrobat 3.0 PDF files (PDF format version 1.2).
Type 3 Type 3 font (also known as PostScript Type 3 or PS3, T3 or Adobe Type 3) consists of glyphs defined using the full PostScript language, rather than just a subset. Because of this, a Type 3 font can do some things that Type 1 fonts cannot do, such as specify shading, color, and fill patterns. However, it does not support hinting. Adobe Type Manager did not support Type 3 fonts, and they are not supported as native WYSIWYG fonts on any version of macOS or Windows.
Type 4 Type 4 is a format that was used to make fonts for printer font cartridges and for permanent storage on a printer's hard disk. The character descriptions are expressed in the Type 1 format. Adobe does not document this proprietary format.
Type 5 Type 5 is similar to the Type 4 format but is used for fonts stored in the ROMs of PostScript printers, also known as compressed ROM (CROM) fonts.
Types 9, 10, 11 Ghostscript referred them as CID font types 0, 1, and 2 respectively, documented in Adobe supplements. Types 9, 10, and 11 are CID-keyed fonts for storing Types 1, 3, and 42, respectively.
Type 14 Type 14, or the Chameleon font format, is used to represent a large number of fonts in a small amount of storage space such as printer ROM. The core set of Chameleon fonts consists of one Master Font, and a set of font descriptors that specify how the Master Font is to be adjusted to give the desired set of character shapes for a specific typeface.
Adobe does not document the Type 14 format. It was introduced with PostScript 3 in 1997, and de-emphasized in later years as storage became cheaper.
Type 32 Type 32 is used for downloading bitmap fonts to PostScript interpreters with version number 2016 or greater. The bitmap characters are transferred directly into the interpreter's font cache, thus saving space in the printer's memory.
Type 42 The Type 42 font format is a PostScript wrapper around a TrueType font, allowing PostScript-capable printers containing a TrueType rasterizer (which was first implemented in PostScript interpreter version 2010 as an optional feature, later standard) to print TrueType fonts. Support for multibyte CJK TrueType fonts was added in PostScript version 2015. The out-of-sequence choice of the number 42 is said to be a jesting reference to The Hitchhiker's Guide to the Galaxy, where 42 is the Answer to Life, the Universe, and Everything.
Core Font Set In addition to font types, PostScript specifications also defined the Core Font Set, which dictates the minimum number of fonts, and character sets to be supported by each font.
PostScript Level 1 The original PostScript language reference manual defined 13 font styles in four families:
Courier (Regular, Oblique, Bold, Bold Oblique) Helvetica (Regular, Oblique, Bold, Bold Oblique) Times (Roman, Italic, Bold, Bold Italic) Symbol
PostScript Level 2 PostScript Level 2 defined 35 font styles which form 10 type families. They include all of the above Level 1 fonts, plus the following:
ITC Avant Garde Gothic (Book, Book Oblique, Demi, Demi Oblique) ITC Bookman (Light, Light Italic, Demi, Demi Italic) Helvetica (Narrow, Narrow Oblique, Narrow Bold, Narrow Bold Oblique, in addition to the 4 font styles in PostScript Level 1) New Century Schoolbook (Roman, Italic, Bold, Bold Italic) Palatino (Roman, Italic, Bold, Bold Italic) ITC Zapf Chancery (Medium Italic) ITC Zapf Dingbats
Some level 1 printers such as the Apple LaserWriter Plus included this set of fonts. Many computer operating systems have these fonts installed, while various projects have created clones of them. For instance, the Ghostscript fonts (also known as the URW Base 35 fonts) are open-source clones of all fonts defined in PostScript 2.
PostScript Level 3 In PostScript 3, 136 font styles are specified, which include the 35 font styles defined in PostScript 2, core fonts in popular operating systems (namely Windows 95, Windows NT, and Macintosh), selected fonts from Microsoft Office, and the HP 110 font set. New fonts include:
Albertus (Light, Roman, Italic) Antique Olive (Roman, Italic, Bold, Compact) Apple Chancery Arial (Regular, Italic, Bold, Bold Italic) Bodoni (Roman, Italic, Bold, Bold Italic, Poster, Poster Compressed) Carta (a dingbat) Chicago Clarendon (Light, Roman, Bold) Cooper Black, Cooper Black Italic Copperplate Gothic (32BC, 33BC) Coronet Eurostile (Medium, Bold, Extended No.2, Bold Extended No.2) Geneva Gill Sans (Light, Light Italic, Book, Book Italic, Bold, Bold Italic, Extra Bold, Condensed, Condensed Bold) Goudy (Oldstyle, Oldstyle Italic, Bold, Bold Italic, Extra Bold) Helvetica (Condensed, Condensed Oblique, Condensed Bold, Condensed Bold Oblique) Hoefler Text (Roman, Italic, Black, Black Italic), Hoefler Ornaments Joanna (Roman/Regular, Italic, Bold, Bold Italic) Letter Gothic (Regular, Slanted, Bold, Bold Slanted) ITC Lubalin Graph (Book, Oblique, Demi, Demi Oblique) ITC Mona Lisa Recut Marigold Monaco New York Optima (Roman, Italic, Bold, Bold Italic) Oxford Stempel Garamond (Roman, Italic, Bold, Bold Italic) Tekton (Regular) Times New Roman (Regular, Italic, Bold, Bold Italic) Univers (45 Light, 45 Light Oblique, 55, 55 Oblique, 65 Bold, 65 Bold Oblique, 57 Condensed, 57 Condensed Oblique, 67 Condensed Bold, 67 Condensed Bold Oblique, 53 Extended, 53 Extended Oblique, 63 Extended Bold, 63 Extended Bold Oblique) Wingdings
Others In PDF, 14 Type 1 fonts are defined as the standard fonts. They include the 13 font styles defined by PostScript Level 1, along with ITC Zapf Dingbats.
However, in recent versions of Adobe Acrobat Reader, Helvetica and Times were internally replaced by Arial and Times New Roman respectively.
Character sets Although PostScript fonts can contain any character set, there are character sets specifically developed by Adobe, which are used by fonts developed by Adobe.
Adobe Western 2 It includes a basic character set containing upper and lowercase letters, figures, accented characters, and punctuation. These fonts also contain currency symbols (cent, dollar, euro, florin, pound sterling, yen), standard ligatures (fi, fl), common fractions (1/4, 1/2, 3/4), common mathematics operators, superscript numerals (1,2,3), common delimiters and conjoiners, and other symbols (including daggers, trademark, registered trademark, copyright, paragraph, litre and estimated symbol). Compared to the ISO-Adobe character set, Western 2 also adds 17 additional symbol characters: euro, litre, estimated, omega, pi, partialdiff, delta, product, summation, radical, infinity, integral, approxequal, notequal, lessequal, greaterequal, and lozenge.
Fonts with an Adobe Western 2 character set support most western languages including Afrikaans, Basque, Breton, Catalan, Danish, Dutch, English, Finnish, French, Gaelic, German, Icelandic, Indonesian, Irish, Italian, Norwegian, Portuguese, Sami, Spanish, Swahili and Swedish.
This standard superseded ISO-Adobe as the new minimum character set standard as implemented in OpenType fonts from Adobe.
Adobe CE