Editing PostScript (section)

=== Font handling ===
{{Main|PostScript fonts}}
Almost as complex as PostScript itself is its handling of [[typeface|fonts]]. The font system uses the PS graphics primitives to draw glyphs as curves, which can then be rendered at any [[Image resolution|resolution]]. A number of [[typographic]] issues had to be considered with this approach.

One issue is that fonts do not scale linearly at small sizes and features of the glyphs will become proportionally too large or small and start to look displeasing. PostScript avoided this problem with the inclusion of [[font hinting]], in which additional information is provided in horizontal or vertical bands to help identify the features in each letter that are important for the rasterizer to maintain. The result was significantly better-looking fonts even at low resolution. It had formerly been believed that hand-tuned bitmap fonts were required for this task.

At the time, the technology for including these hints in fonts was carefully guarded, and the hinted fonts were compressed and encrypted into what Adobe called a ''[[Type 1 Font]]'' (also known as ''PostScript Type 1 Font'', ''PS1'', ''T1'' or ''Adobe Type 1''). Type 1 was effectively a simplification of the PS system to store outline information only, as opposed to being a complete language (PDF is similar in this regard). Adobe would then sell licenses to the Type 1 technology to those wanting to add hints to their own fonts. Those who did not license the technology were left with the ''[[Type 3 Font]]'' (also known as ''PostScript Type 3 Font'', ''PS3'' or ''T3''). Type 3 fonts allowed for all the sophistication of the PostScript language, but without the standardized approach to hinting.

The [[Type 2 font]] format was designed to be used with [[Compact Font Format]] (CFF) charstrings, and was implemented to reduce the overall font file size. The [[CFF/Type 2 font|CFF/Type2]] format later became the basis for handling PostScript outlines in [[OpenType]] fonts.

The [[CID-keyed font]] format was also designed, to solve the problems in the [[OCF/Type 0 font]]s, for addressing the complex Asian-language ([[CJK]]) encoding and very large character set issues. The CID-keyed font format can be used with the Type 1 font format for standard CID-keyed fonts, or Type 2 for CID-keyed OpenType fonts.

To compete with Adobe's system, Apple designed their own system, [[TrueType]], around 1991. Immediately following the announcement of TrueType, Adobe published the specification for the Type 1 font format. Retail tools such as Altsys [[Fontographer]] (acquired by [[Macromedia]] in January 1995, owned by [[FontLab]] since May 2005) added the ability to create Type 1 fonts. Since then, many free Type 1 fonts have been released; for instance, the fonts used with the [[TeX]] typesetting system are available in this format.

In the early 1990s, there were several other systems for storing outline-based fonts, developed by [[Bitstream Inc.|Bitstream]] and [[Metafont]] for instance, but none included a general-purpose printing solution and they were therefore not widely used.

In the late 1990s, Adobe joined Microsoft in developing [[OpenType]], essentially a functional superset of the Type 1 and TrueType formats. When printed to a PostScript output device, the unneeded parts of the OpenType font are omitted, and what is sent to the device by the driver is the same as it would be for a TrueType or Type 1 font, depending on which kind of outlines were present in the OpenType font.

Adobe supported Type 1 fonts in its products until January 2023, when it fully removed support in favor of OpenType fonts.<ref>{{cite web |title=PostScript Type 1 fonts end of support |url=https://helpx.adobe.com/uk/fonts/kb/postscript-type-1-fonts-end-of-support.html |website=Adobe |access-date=2 March 2024}}</ref>