diff --git a/hugo.yaml b/hugo.yaml
index 1571c35..ccde420 100644
--- a/hugo.yaml
+++ b/hugo.yaml
@@ -191,6 +191,21 @@ params:
         - name: go-slides
           url: https://go-slides.github.io/
           logo: images/brand/svg/go-slides.svg
+        # The sister orgs' marks are their brand repositories' svg/color files,
+        # copied verbatim into static/images/brand/svg/ (go-slides' own comes
+        # through the branding submodule).
+        - name: go-tex
+          url: https://go-tex.github.io/
+          logo: images/brand/svg/go-tex.svg
+        - name: go-richdoc
+          url: https://go-richdoc.github.io/
+          logo: images/brand/svg/go-richdoc.svg
+        - name: go-docutils
+          url: https://go-docutils.github.io/
+          logo: images/brand/svg/go-docutils.svg
+        - name: go-pdfkit
+          url: https://go-pdfkit.github.io/
+          logo: images/brand/svg/go-pdfkit.svg
 
   theme:
     default: system
diff --git a/static/images/brand/svg/go-docutils.svg b/static/images/brand/svg/go-docutils.svg
new file mode 100644
index 0000000..dace2dc
--- /dev/null
+++ b/static/images/brand/svg/go-docutils.svg
@@ -0,0 +1,14 @@
+<svg viewBox="0 0 256 256" xmlns="http://www.w3.org/2000/svg" role="img" aria-label="go-docutils">
+  <defs><linearGradient id="docutils" x1="0" y1="0" x2="1" y2="1">
+    <stop offset="0" stop-color="#6366F1"/><stop offset="1" stop-color="#312E81"/></linearGradient></defs>
+  <rect width="256" height="256" rx="56" fill="url(#docutils)"/>
+  <!-- reStructuredText in, doctree out: a page becomes a tree of nodes. -->
+  <g fill="none" stroke="#FFFFFF" stroke-width="12" stroke-linecap="round" stroke-linejoin="round">
+    <rect x="34" y="56" width="72" height="144" rx="12"/>
+    <path d="M50 88 H90"/><path d="M50 122 H90"/><path d="M50 156 H78"/>
+    <path d="M118 128 H150"/>
+    <path d="M172 128 V88 H196"/>
+    <path d="M172 128 V168 H196"/>
+  </g>
+  <g fill="#FFFFFF"><circle cx="164" cy="128" r="11"/><circle cx="206" cy="88" r="11"/><circle cx="206" cy="168" r="11"/></g>
+</svg>
diff --git a/static/images/brand/svg/go-pdfkit.svg b/static/images/brand/svg/go-pdfkit.svg
new file mode 100644
index 0000000..11add9c
--- /dev/null
+++ b/static/images/brand/svg/go-pdfkit.svg
@@ -0,0 +1,16 @@
+<svg viewBox="0 0 256 256" xmlns="http://www.w3.org/2000/svg" role="img" aria-label="go-pdfkit">
+  <defs>
+    <linearGradient id="pdfred" x1="0" y1="0" x2="1" y2="1">
+      <stop offset="0" stop-color="#EF4444"/>
+      <stop offset="1" stop-color="#991B1B"/>
+    </linearGradient>
+  </defs>
+  <rect width="256" height="256" rx="56" fill="url(#pdfred)"/>
+  <g fill="none" stroke="#FFFFFF" stroke-linecap="round" stroke-linejoin="round" stroke-width="11">
+    <path d="M78 54H150L184 88V202H78Z"/>
+    <path d="M150 54V88H184"/>
+    <line x1="98" y1="128" x2="164" y2="128"/>
+    <line x1="98" y1="152" x2="164" y2="152"/>
+    <line x1="98" y1="176" x2="140" y2="176"/>
+  </g>
+</svg>
diff --git a/static/images/brand/svg/go-richdoc.svg b/static/images/brand/svg/go-richdoc.svg
new file mode 100644
index 0000000..d119920
--- /dev/null
+++ b/static/images/brand/svg/go-richdoc.svg
@@ -0,0 +1,13 @@
+<svg viewBox="0 0 256 256" xmlns="http://www.w3.org/2000/svg" role="img" aria-label="go-richdoc">
+  <defs><linearGradient id="richdoc" x1="0" y1="0" x2="1" y2="1">
+    <stop offset="0" stop-color="#4F46E5"/><stop offset="1" stop-color="#1E1B4B"/></linearGradient></defs>
+  <rect width="256" height="256" rx="56" fill="url(#richdoc)"/>
+  <!-- One document model that every format converts INTO: arrows converge on the page. -->
+  <g fill="none" stroke="#FFFFFF" stroke-width="12" stroke-linecap="round" stroke-linejoin="round">
+    <rect x="94" y="94" width="68" height="68" rx="12"/>
+    <path d="M30 128 H74"/><path d="M74 128 L60 118"/><path d="M74 128 L60 138"/>
+    <path d="M226 128 H182"/><path d="M182 128 L196 118"/><path d="M182 128 L196 138"/>
+    <path d="M128 30 V74"/><path d="M128 74 L118 60"/><path d="M128 74 L138 60"/>
+    <path d="M128 226 V182"/><path d="M128 182 L118 196"/><path d="M128 182 L138 196"/>
+  </g>
+</svg>
diff --git a/static/images/brand/svg/go-tex.svg b/static/images/brand/svg/go-tex.svg
new file mode 100644
index 0000000..a928e3d
--- /dev/null
+++ b/static/images/brand/svg/go-tex.svg
@@ -0,0 +1,9 @@
+<svg viewBox="0 0 256 256" xmlns="http://www.w3.org/2000/svg" role="img" aria-label="go-tex">
+  <defs><linearGradient id="g" x1="0" y1="0" x2="1" y2="1"><stop offset="0" stop-color="#4F46E5"/><stop offset="1" stop-color="#1E1B4B"/></linearGradient></defs>
+  <rect width="256" height="256" rx="56" fill="url(#g)"/>
+  <g fill="#FFFFFF" font-family="Georgia,'Times New Roman',serif" font-weight="700">
+    <text x="44" y="150" font-size="96">T</text>
+    <text x="98" y="176" font-size="96">E</text>
+    <text x="156" y="150" font-size="96">X</text>
+  </g>
+</svg>