diff --git c/lib/matplotlib/mpl-data/latex/underscore.sty i/lib/matplotlib/mpl-data/latex/underscore.stynew file mode 100644index 000000000..f0cfb895d--- /dev/null+++ i/lib/matplotlib/mpl-data/latex/underscore.sty@@ -0,0 +1,248 @@+% underscore.sty     21-Sep-2005   Donald Arseneau   asnd@triumf.ca+% Make the "_" character print as "\textunderscore" in text.+% Copyright 1998,2001,2005,2006 Donald Arseneau;+% License: LPPL version 1.2 or later.+% Instructions follow after the definitions.++\ProvidesPackage{underscore}[2006/09/13]++\begingroup+ \catcode`\_=\active+ \gdef _{% \relax % No relax gives a small vulnerability in alignments+   \ifx\if@safe@actives\iftrue % must be outermost test!+      \string_%+   \else+      \ifx\protect\@typeset@protect+         \ifmmode \sb \else \BreakableUnderscore \fi+      \else+         \ifx\protect\@unexpandable@protect \noexpand_%+         \else \protect_%+      \fi\fi+    \fi}+  \global\let\ActiveUnderscore=_+  \gdef\normalUnderscoreDef{\let_\ActiveUnderscore}+\endgroup++% At begin: set catcode; fix \long \ttdefault so I can use it in comparisons;+% reapply definition of active _ in output routine (\@firstofone to strip+% away braces, so avoiding deeper nesting).+\AtBeginDocument{%+  {\immediate\write\@auxout{\catcode\number\string`\_ \string\active}}%+  \catcode\string`\_\string=\active+  \edef\ttdefault{\ttdefault}%+  \output=\expandafter\expandafter\expandafter+     {\expandafter\expandafter\expandafter\normalUnderscoreDef+      \expandafter\@firstofone\the\output}%+}++\newcommand{\BreakableUnderscore}{\leavevmode\nobreak\hskip\z@skip+ \ifx\f@family\ttdefault \string_\else \textunderscore\fi+ \usc@dischyph\nobreak\hskip\z@skip}++\DeclareRobustCommand{\_}{%+  \ifmmode \nfss@text{\textunderscore}\else \BreakableUnderscore \fi}+++\let\usc@dischyph\@dischyph+\DeclareOption{nohyphen}{\def\usc@dischyph{\discretionary{}{}{}}}+\DeclareOption{strings}{\catcode`\_=\active}++\ProcessOptions+\ifnum\catcode`\_=\active\else \endinput \fi++%%%%%%%%   Redefine commands that use character strings   %%%%%%%%++\@ifundefined{UnderscoreCommands}{\let\UnderscoreCommands\@empty}{}+\expandafter\def\expandafter\UnderscoreCommands\expandafter{%+  \UnderscoreCommands+  \do\include \do\includeonly+  \do\@input \do\@iinput \do\InputIfFileExists+  \do\ref \do\pageref \do\newlabel+  \do\bibitem \do\@bibitem \do\cite \do\nocite \do\bibcite+  \do\Ginclude@graphics \do\@setckpt+}++% Macro to redefine a macro to pre-process its string argument+% with \protect -> \string.+\def\do#1{% Avoid double processing if user includes command twice!+ \@ifundefined{US\string_\expandafter\@gobble\string#1}{%+   \edef\@tempb{\meaning#1}% Check if macro is just a protection shell...+   \def\@tempc{\protect}%+   \edef\@tempc{\meaning\@tempc\string#1\space\space}%+   \ifx\@tempb\@tempc % just a shell: hook into the protected inner command+     \expandafter\do+       \csname \expandafter\@gobble\string#1 \expandafter\endcsname+   \else % Check if macro takes an optional argument+     \def\@tempc{\@ifnextchar[}%+     \edef\@tempa{\def\noexpand\@tempa####1\meaning\@tempc}%+     \@tempa##2##3\@tempa{##2\relax}%+     \edef\@tempb{\meaning#1\meaning\@tempc}%+     \edef\@tempc{\noexpand\@tempd \csname+        US\string_\expandafter\@gobble\string#1\endcsname}%+     \if \expandafter\@tempa\@tempb \relax 12\@tempa % then no optional arg+       \@tempc #1\US@prot+     \else  % There is optional arg+       \@tempc #1\US@protopt+     \fi+   \fi+ }{}}++\def\@tempd#1#2#3{\let#1#2\def#2{#3#1}}++\def\US@prot#1#2{\let\@@protect\protect \let\protect\string+  \edef\US@temp##1{##1{#2}}\restore@protect\US@temp#1}+\def\US@protopt#1{\@ifnextchar[{\US@protarg#1}{\US@prot#1}}+\def\US@protarg #1[#2]{\US@prot{{#1[#2]}}}++\UnderscoreCommands+\let\do\relax \let\@tempd\relax  % un-do++%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%++\endinput++underscore.sty    13-Sep-2006  Donald Arseneau++Features:+~~~~~~~~~+The "\_" command (which normally prints an underscore character or+facsimile) is altered so that the hyphenation of constituent words+is not affected, and hyphenation is permitted after the underscore.+For example, "compound\_fracture" hyphenates as com- pound\_- frac- ture.+If you prefer the underscore to break without a hyphen (but still with+the same rules for explicit hyphen-breaks) then use the [nohyphen]+package option.++A simple "_" acts just like "\_" in text mode, but makes a subscript+in math mode: activation_energy $E_a$++Both forms use an underscore character if the font encoding contains+one (e.g., "\usepackage[T1]{fontenc}" or typewriter fonts in any encoding),+but they use a rule if there is no proper character.++Deficiencies:+~~~~~~~~~~~~~+The skips and penalties ruin any kerning with the underscore character+(when a character is used).  However, there doesn't seem to be much, if+any, such kerning in the ec fonts, and there is never any kerning with+a rule.++You must avoid "_" in file names and in cite or ref tags, or you must use+the babel package, with its active-character controls, or you must give+the [strings] option, which attempts to redefine several commands (and+may not work perfectly).  Even without the [strings] option or babel, you+can use occasional underscores like: "\include{file\string_name}".++Option: [strings]+~~~~~~~~~~~~~~~~~+The default operation is quite simple and needs no customization; but+you must avoid using "_" in any place where LaTeX uses an argument as+a string of characters for some control function or as a name.  These+include the tags for "\cite" and "\ref", file names for "\input",+"\include", and "\includegraphics", environment names, counter names,+and placement parameters (like "[t]").  The problem with these contexts+is that they are `moving arguments' but LaTeX does not `switch on' the+"\protect" mechanism for them.++If you need to use the underscore character in these places, the package+option [strings] is provided to redefine commands that take such a string+argument so that protection is applied (with "\protect" being "\string").+The list of commands is given in "\UnderscoreCommands", with "\do" before+each; plus several others covering "\input", "\includegraphics, "\cite",+"\ref", and their variants.  Not included are many commands regarding font+names, everything with counter names, environment names, page styles, and+versions of "\ref" and "\cite" defined by external packages (e.g., "\vref"+and "\citeyear").++You can add to the list of supported commands by defining "\UnderscoreCommands"+before loading this package; e.g.++   \usepackage{chicago}+   \newcommand{\UnderscoreCommands}{%   (\cite already done)+     \do\citeNP \do\citeA \do\citeANP \do\citeN \do\shortcite+     \do\shortciteNP \do\shortciteA \do\shortciteANP \do\shortciteN+     \do\citeyear \do\citeyearNP+   }+   \usepackage[strings]{underscore}++Not all commands can be supported this way!  Only commands that take a+string argument *first* can be protected.  One optional argument before+the string argument is also permitted, as exemplified by "\cite": both+"\cite{tags}" and "\cite[text]{tags}" are allowed.  A command like+"\@addtoreset" which takes two counter names as arguments could not+be protected by listing it in "\UnderscoreCommands".++*When you use the [strings] option, you must load this package+last* (or nearly last).++There are two reasons: 1) The redefinitions done for protection must come+after other packages define their customized versions of those commands.+2) The [strings] option requires the "_" character to be activated immediately+in order for the cite and ref tags to be read properly from the .aux file+as plain strings, and this catcode setting might disrupt other packages.++The babel package implements a protection mechanism for many commands,+and will be a complete fix for most documents without the [strings] option.+Many add-on packages are compatible with babel, so they will get the+strings protection also.  However, there are several commands that are+not covered by babel, but can easily be supported by the [strings] and+"\UnderscoreCommands" mechanism.  Beware that using both [strings] and+babel might lead to conflicts, but none are seen yet (load babel last).++Implementation Notes:+~~~~~~~~~~~~~~~~~~~~~+The first setting of "_" to be an active character is performed in a local+group so as to not interfere with other packages.  The catcode setting+is repeated with "\AtBeginDocument" so the definition is in effect for the+text.  However, the catcode setting is repeated immediately when the+[strings] option is detected.++The definition of the active "_" is essentially:++       \ifmmode \sb \else \BreakableUnderscore \fi++where "\sb" retains the normal subscript meaning of "_" and where+"\BreakableUnderscore" is essentially "\_".  The rest of the definition+handles the "\protect"ion without causing "\relax" to be inserted before+the character.++"\BreakableUnderscore" uses "\nobreak\hskip\z@skip" to separate the+underscore from surrounding words, thus allowing TeX to hyphenate them,+but preventing free breaks around the underscore. Next, it checks the+current font family, and uses the underscore character from tt fonts or+otherwise "\textunderscore" (which is a character or rule depending on+the font encoding).  After the underscore, it inserts a discretionary+hyphenation point as "\usc@dischyph", which is usually just "\-"+except that it still works in the tabbing environment, although it+will give "\discretionary{}{}{}" under the [nohyphen] option.  After+that, another piece of non-breaking interword glue is inserted.+Ordinarily, the comparison "\ifx\f@family\ttdefault" will always fail+because "\ttdefault" is `long' whereas "\f@family" is not (boooo hisss),+but "\ttdefault" is redefined to be non-long by "\AtBeginDocument".++The "\_" command is then defined to use "\BreakableUnderscore".++If the [strings] option is not given, then that is all!++Under the [strings] option, the list of special commands is processed to:++ - retain the original command as "\US_"*command* (e.g., "\US_ref")+ - redefine the command as "\US@prot\US_command" for ordinary commands+   ("\US@prot\US_ref") or as "\US@protopt\US_command" when an optional+   argument is possible (e.g., "\US@protopt\US_bibitem").+ - self-protecting commands ("\cite") retain their self-protection.++Diagnosing the state of the pre-existing command is done by painful+contortions involving "\meaning".++"\US@prot" and "\US@protopt" read the argument, process it with+"\protect" enabled, then invoke the saved "\US_command".++Modifications:+~~~~~~~~~~~~~~+13-Sep-2006  Reassert my definition in the output routine (listings).+21-Sep-2005  \includegraphics safe.+12-Oct-2001  Babel (safe@actives) compatibility and [nohyphen] option.++Test file integrity:  ASCII 32-57, 58-126:  !"#$%&'()*+,-./0123456789+:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~diff --git c/lib/matplotlib/texmanager.py i/lib/matplotlib/texmanager.pyindex 254a36fb8..04ef1869a 100644--- c/lib/matplotlib/texmanager.py+++ i/lib/matplotlib/texmanager.py@@ -34,6 +34,7 @@ import logging import os from pathlib import Path import re+import shutil import subprocess from tempfile import TemporaryDirectory@@ -191,6 +192,7 @@ class TexManager:             # geometry is loaded before the custom preamble as convert_psfrags             # relies on a custom preamble to change the geometry.             r"\usepackage[papersize=72in, margin=1in]{geometry}",+            r"\usepackage{underscore}",             self.get_custom_preamble(),             # textcomp is loaded last (if not already loaded by the custom             # preamble) in order not to clash with custom packages (e.g.@@ -312,6 +314,8 @@ class TexManager:             # final output dir ensures that they are on the same filesystem,             # and thus replace() works atomically.             with TemporaryDirectory(dir=Path(dvifile).parent) as tmpdir:+                shutil.copy(+                    cbook._get_data_path("latex/underscore.sty"), tmpdir)                 self._run_checked_subprocess(                     ["latex", "-interaction=nonstopmode", "--halt-on-error",                      texfile], tex, cwd=tmpdir)@@ -334,6 +338,8 @@ class TexManager:          if not os.path.exists(dvifile) or not os.path.exists(baselinefile):             texfile = self.make_tex_preview(tex, fontsize)+            shutil.copy(cbook._get_data_path("latex/underscore.sty"),+                        Path(texfile).parent)             report = self._run_checked_subprocess(                 ["latex", "-interaction=nonstopmode", "--halt-on-error",                  texfile], tex)