Add whatsnew entry for Type42 subsetting

aitikgupta · aitikgupta · commit 09384974758d · 2021-07-14T12:38:24.000+05:30
diff --git a/doc/users/next_whats_new/subsetting.rst b/doc/users/next_whats_new/subsetting.rst
@@ -0,0 +1,22 @@
+Type 42 Subsetting is now enabled for PDF/PS backends
+-----------------------------------------------------
+
+`~matplotlib.backends.backend_pdf` and `~matplotlib.backends.backend_ps` now use
+a unified Type 42 font subsetting interface, with the help of `fontTools <https://fonttools.readthedocs.io/en/latest/>`_
+
+Set `~matplotlib.RcParams`'s *fonttype* value as ``42`` to trigger this workflow:
+
+.. code-block::
+
+    # for PDF backend
+    plt.rcParams['pdf.fonttype'] = 42
+
+    # for PS backend
+    plt.rcParams['ps.fonttype'] = 42
+
+
+    fig, ax = plt.subplots()
+    ax.text(0.4, 0.5, 'subsetted document is smaller in size!')
+
+    fig.savefig("document.pdf")
+    fig.savefig("document.ps")
