The text-producing systems

LaTeX Latex is an emulsion (stable dispersion) of polymer microparticles in water. Latexes are found in nature, but synthetic latexes are common as well. In nature, latex is found as a milky fluid found in 10% of all flowering plants (angiosper ...

and TeX produce DVI files from files written by the user. Those files used to be (and, to a moderate extent, still are) post-processed by a tool called

dvips dvips is a computer program that converts the Device Independent file format (DVI) output of TeX typography into a printable or otherwise presentable form. was written by Tomas Rokicki to produce printable PostScript files from DVI input, and ...

, which converted those DVI files into

PostScript PostScript (PS) is a page description language in the electronic publishing and desktop publishing realm. It is a dynamically typed, concatenative programming language. It was created at Adobe Systems by John Warnock, Charles Geschke, ...

files, which are understood by many printers. Some older versions of

with embedded bitmapped fonts, which represented letters and symbols as pictures at a fixed resolution (for instance, at 300 dpi). When such files are printed on newer devices (some with resolution of 1200 dpi), the letters of the files that have bitmapped fonts display a remarkably low quality, with jagged lines on curves and diagonals. One solution to this problem is to substitute the bitmapped fonts with scalable fonts (known among PostScript users as

Type 1 font PostScript fonts are font files encoded in outline font specifications developed by Adobe Systems for professional digital typesetting. This system uses PostScript file format to encode font information. "PostScript fonts" may also separately ...

s). To remedy this problem of low quality printing, one can use Heiko Oberdiek's utility called pkfix. The input of pkfix is a PostScript file generated by dvips (with versions at 5.58 or newerDocumentation of pkfix on CTAN.
/ref>) and its output is another PostScript file, this time, with the bitmapped fonts substituted by scalable fonts (if possible). Technically speaking, pkfix is a

Perl Perl is a family of two High-level programming language, high-level, General-purpose programming language, general-purpose, Interpreter (computing), interpreted, dynamic programming languages. "Perl" refers to Perl 5, but from 2000 to 2019 it ...

script which searches the PostScript file for comments on bitmapped

PK fonts PK or pk may refer to: Arts and entertainment Gaming * Probability of kill (Pk), in computer games, simulations, models, and operations research * '' Disney's PK: Out of the Shadows'', a 2002 video game * Player killing, player versus player conf ...

(introduced by relatively recent dvips versions), and replaces them with the corresponding Type 1 fonts. Of course, a simpler solution to this problem would be to reprocess the LaTeX/TeX files with recent tools and fonts, but, in most cases, the person that has the given PostScript file isn't the author of the document and doesn't have access to the source files (or, worse, the source files may have been lost during the times).

References

{{reflist Font formats PostScript Software using the LPPL license