man page mf-nowin section 1

mf(1)                       General Commands Manual                      mf(1)

NAME

       mf, inimf, mf-nowin - Metafont, a language for font and logo design

SYNOPSIS

       mf [options] [&base]  [ file [ more-input ] | [ \more-input ]

DESCRIPTION

Metafont reads the source program in the specified files and outputs
font bitmaps in gf (generic font) format and font metrics in tfm (TeX
font metric) format. The Metafont language is described in The
Metafontbook. In general, Metafont programs describe how to draw
characters in fonts, or other shapes, in an algorithmic way.

The normal usage is to run

mf '\mode=printengine; [mag=magstep(n);]' input font

to process font.mf with Metafont.

mf's command line processing is essentially the same as TeX's, except
that the conventional assignment to mode on the command line means that
it's usual to invoke mf with several commands, as shown, and not just a
filename. Without the initial backslash, Metafont would try to read a
file name mode, just as TeX would. On Unix, the single quotes are the
simplest way of keeping the shell from (mis)interpreting the backslash,
semicolons, parentheses, etc. Alternatively, you can invoke mf without
arguments and give the commands on the next line, in response to mf's
"**" prompt, without any quotes.

In either case, other Metafont commands, such as batchmode (for silent
operation) can also appear. The default extension, ".mf", can be
overridden by specifying an extension explicitly.

The name font will be the ``jobname'', and is used in forming output
file names. If Metafont doesn't get a file name in the first line, the
jobname is mfput. A log of error messages goes into the file
jobname.log. The output files are jobname.tfm (for the metrics) and
jobname.<number>gf (for the bitmaps), where <number> depends on the
resolution and magnification of the generated font.

Metafont can also be invoked by TeX, via the (for example) mktextfm(1)
script (q.v.), when TeX cannot find a font.

Metafont's output

Internally, Metafont computes Bezier cubic splines (and straight lines)
from the Metafont source program. However, as mentioned above, the main
output from Metafont is a bitmap file, that is, given the desired
output device (see next section), Metafont does its own rasterization.
(Why? Because Knuth's goal in creating TeX and Metafont was to
completely control the typesetting of his own books, down to the
pixel.)

On the other hand, nowadays it is almost universal to want outline
fonts in the pdf (or other) output from TeX (or other document
processors). It is possible to extract the splines that Metafont
computes from its log file, or to have Metafont generate a high-
resolution bitmap and trace that (with, e.g., autotrace(1)), to get
back to splines, but both of these are inconvenient, at best. It is
easier to use MetaPost (mpost(1)), which outputs PostScript instead of
bitmaps, and outputs the splines instead of their rasterizations.
Metafont sources cannot generally be used without change with MetaPost,
but they are close. A detailed article on this, in a relatively early
project, is by Richard Kinch: MetaFog: Converting Metafont shapes to
contours, TUGboat 16:3, https://tug.org/TUGboat/tb16-3/tb48kinc.pdf).

The tfm font metrics file that Metafont outputs contains character
dimension (height, width, depth) information, along with ligatures,
kerns, and so on; in short, everything needed to do typesetting with
the font. This does not include the shapes themselves. OpenType and
TrueType fonts, by contrast, incorporate both metric and shape
information, along with (potentially) a whole lot more for typesetting
in non-Latin scripts, which the original TeX and Metafont do not
attempt to handle, in modern generality. (There have been many projects
to do typesetting with TeX in non-Latin scripts, both predating Unicode
and working with Unicode when it became available. Articles in TUGboat
can be found at
https://tug.org/TUGboat/Contents/listkeyword.html#CatTAGMultilingualDocumentProcessing.)

The technical specifications of the gf (bitmap) and tfm (metrics)
formats are in the Metafont source program, or any of the utility
programs working with the respective formats; see list at end.

Modes (device definitions)

The Metafont mode of printengine in the above invocation needs to be
the name of an actual device (e.g., ljfour) or localfont. If a mode is
not specified, or is not valid, Metafont will default to proof mode,
which produces large character images for use in font design. Proof
mode will generate an output file of .2602gf (36 pixels per point). A
proof mode gf can be further processed into a printable document with
gftodvi(1). This proof mode output is described further in The
Metafontbook, Appendix H (Hardcopy Proofs), and examples for the entire
Computer Modern typeface family are shown in Computer Modern Typefaces
(Volume E of Computers & Typesetting).

Modes are defined with the mode_def macro, which adapts the font output
to a particular output device, by defining such things as the device
resolution. The file modes.mf (https://ctan.org/pkg/modes) is
distributed with TeX Live and is used by default; it describes the
various parameters, defines more than 150 modes (more entries are
welcome), and defines localfont as ljfour, a 600dpi HP LaserJet
printer.

Nowadays, output is often viewed online, where high-resolution bitmaps
are desirable. Several definitions in modes.mf can be used for this:
the mode named pdf (or dpdfezzz for older versions) generates bitmaps
at 8000 dpi (other parameters are canonical). If you want a lower
resolution, similar canonical modes are supre at 2400 and ultre at
1200.

The Metafontbook gives some more details and examples of modes,
particularly in chapter 11 (Magnification and Resolution).

Magsteps

The system of magsteps is identical to what is used in TeX, with values
of n in the above invocation generally one of 0.5, 1, 2, 3, 4 or 5,
although in principle it can be anything. Magnification can also be
specified not as a call to magstep but as an arbitrary value, such as
1.315, to create special character sizes. It can also be entirely
omitted, as shown above.

Base (.base) selection

Like TeX, Metafont is normally used with a large body of precompiled
macros, called a "base"; the plain base is distributed as part of
Metafont and is by far the most commonly used.

The Metafont implementation in TeX Live (a.k.a. Web2C) looks at its
command line to see what name it was called under, just as TeX does.
In short, The names inimf and virmf read plain.base, and any other name
reads the base file by that name. See tex(1) for details. The
invocation name mf-nowin is a case special to Metafont that uses
mf.base; see below.

Error handling

See tex(1); Metafont's error recovery is entirely analogous. The
environment variable name for the editor is MFEDIT.

Online graphics output

Unlike TeX, Metafont can show the results of its processing online, as
it runs. Metafont can use most modern displays. Chapter 23 of The
Metafontbook describes what you can do. Metafont uses environment
variables to determine which display device to use.

First it looks for a variable MFTERM; if MFTERM is not set, and DISPLAY
is set, the Metafont window support for X is used. (DISPLAY must be set
to a valid X server specification, as usual.) If neither MFTERM nor
DISPLAY is set, TERM is used to guess the window support to use. If it
can't find any of these, you get no online output.

The supported values for MFTERM and TERM are listed at
https://tug.org/texinfohtml/web2c.html#Online-Metafont-graphics. Since
they are mostly old and rarely used, and not enabled by default in TeX
Live, the list is not repeated here.

The two Kpathsea configuration variables screen_width and screen_depth
define the width and height of the window used by Metafont. They can be
set in the environment or a Kpathsea configuration file
(https://tug.org/texinfohtml/kpathsea.html#Path-sources). They default
to 1664 and 1200, respectively.

By default, TeX Live is distributed with two Metafont binaries, mf and
mf-nowin. The mf binary supports graphics, while the mf-nowin binary
does not. The mf-nowin binary is used by scripts like mktexpk(1),
where graphics support is a nuisance rather than something helpful.

OPTIONS

       See tex(1) for both details of command-line parsing and the options
       available (apart from the TeX-specific ones). The only Metafont-
       specific option name is -base, which is entirely analogous to TeX's
       -format.

ENVIRONMENT

       See tex(1) for general information and more details. The terse
       descriptions here are just a hint. There are many more environment
       variables that can affect the path searching behavior.

       TEXMFOUTPUT
              If set, Metafont attempts to put its output files here, if they
              cannot be put in the current directory.

       MFINPUTS
              Search path for input files.

       MFEDIT Command template for switching to editor.

       MFTERM Determines the online graphics display. See above.

       screen_width, screen_depth
              Width and height of online graphics window.

FONT UTILITIES

       Here is a selection of the core utility programs that accompany
       Metafont:

       gftopk Takes a gf file and produces a smaller pk font file.

       gftodvi
              Produces proof sheets for fonts.

       gftype Displays the contents of a gf file in mnemonics and/or images.

       pktype Mnemonically displays the contents of a pk file.

       mft    Formats a source file as shown in Computer Modern Typefaces.

FILES

       $TEXMFMAIN/metafont/base/plain.mf
              The standard base.

       $TEXMFMAIN/metafont/misc/modes.mf
              A file of mode_defs for many devices. See
              https://ctan.org/pkg/modes.

       *.base Predigested Metafont base files.

       mf.pool
              Encoded text of Metafont's messages.

BUGS

       Knuth still accepts new bug reports for Metafont, but only reviews them
       every several years. For a list of submitted reports and other
       information: https://tug.org/texmfbug.

HEALTH WARNING

       From The Metafontbook: ``Type design can be hazardous to your other
       interests. Once you get hooked, you will develop intense feelings about
       letterforms; the medium will intrude on the messages that you read. And
       you will perpetually be thinking of improvements to the fonts that you
       see everywhere, especially those of your own design.''

AUTHORS

       Metafont was created by Donald E. Knuth, who implemented it using his
       WEB system for Pascal programs. It was originally ported to Unix by
       Paul Richards at the University of Illinois at Urbana-Champaign. The
       version now included in TeX Live, the current Unix TeX distribution, is
       generated by the Web2C system originally written by Tomas Rokicki and
       Tim Morgan. This man page was originally written by Pierre MacKay.

       Bug reports in Metafont (exceedingly rare): https://tug.org/texmfbug
       Public mailing list for implementation questions and reports:
       https://lists.tug.org/tex-k
       Public discussion list for all things Metafont (and TeX):
       https://lists.tug.org/texhax

Web2C 2026                      15 January 2026                          mf(1)

texlive-bin 2026.78235 - Generated Thu Mar 5 15:49:06 CST 2026