Merge pull request matplotlib#20716 from jkseppan/type1-subset

Type-1 font subsetting

Author: QuLogic

.github/workflows/tests.yml

@@ -64,8 +64,10 @@ jobs:
             python-version: '3.12'
             # https://github.com/matplotlib/matplotlib/issues/29844
             pygobject-ver: '<3.52.0'
-          - os: ubuntu-22.04
+          - name-suffix: "(Extra TeX packages)"
+            os: ubuntu-22.04
             python-version: '3.13'
+            extra-packages: 'texlive-fonts-extra texlive-lang-cyrillic'
             # https://github.com/matplotlib/matplotlib/issues/29844
             pygobject-ver: '<3.52.0'
           - name-suffix: "Free-threaded"
@@ -142,7 +144,8 @@ jobs:
               texlive-latex-recommended \
               texlive-luatex \
               texlive-pictures \
-              texlive-xetex
+              texlive-xetex \
+              ${{ matrix.extra-packages }}
             if [[ "${{ matrix.name-suffix }}" != '(Minimum Versions)' ]]; then
               sudo apt-get install -yy --no-install-recommends ffmpeg poppler-utils
             fi

doc/users/next_whats_new/type1_subset.rst

@@ -0,0 +1,9 @@
+PDF files created with usetex now embed subsets of Type 1 fonts
+---------------------------------------------------------------
+
+When using the PDF backend with the usetex feature,
+Matplotlib calls TeX to render the text and formulas in the figure.
+The fonts that get used are usually "Type 1" fonts.
+They used to be embedded in full
+but are now limited to the glyphs that are actually used in the figure.
+This reduces the size of the resulting PDF files.