diff --git a/Lib/axisregistry/data/x_opaque.textproto b/Lib/axisregistry/data/x_opaque.textproto
index 4d02d5083..26585340c 100644
--- a/Lib/axisregistry/data/x_opaque.textproto
+++ b/Lib/axisregistry/data/x_opaque.textproto
@@ -10,5 +10,6 @@ fallback {
   value: 88
 }
 fallback_only: false
+illustration_url: "x_opaque.svg"
 description:
   "A parametric axis for varying thick stroke weights, such as stems."
diff --git a/Lib/axisregistry/data/x_transparent.textproto b/Lib/axisregistry/data/x_transparent.textproto
index caee90d2e..892686d7c 100644
--- a/Lib/axisregistry/data/x_transparent.textproto
+++ b/Lib/axisregistry/data/x_transparent.textproto
@@ -10,5 +10,6 @@ fallback {
   value: 400
 }
 fallback_only: false
+illustration_url: "x_transparent.svg"
 description:
   "A parametric axis for varying counter widths in the X dimension."
diff --git a/Lib/axisregistry/data/x_transparent_figures.textproto b/Lib/axisregistry/data/x_transparent_figures.textproto
index 9ae978509..69090b1aa 100644
--- a/Lib/axisregistry/data/x_transparent_figures.textproto
+++ b/Lib/axisregistry/data/x_transparent_figures.textproto
@@ -11,4 +11,4 @@ fallback {
 }
 fallback_only: false
 description:
-  "Assigns a 'white' per mille value to each instance of the design space."
\ No newline at end of file
+  "Assigns a 'white' per mille value to each instance of the design space."
diff --git a/Lib/axisregistry/data/y_opaque.textproto b/Lib/axisregistry/data/y_opaque.textproto
index cf7b4bec6..7cfa2b4db 100644
--- a/Lib/axisregistry/data/y_opaque.textproto
+++ b/Lib/axisregistry/data/y_opaque.textproto
@@ -10,5 +10,6 @@ fallback {
   value: 116
 }
 fallback_only: false
+illustration_url: "y_opaque.svg"
 description:
   "A parametric axis for varying thin stroke weights, such as bars and hairlines."
diff --git a/Lib/axisregistry/data/y_transparent_ascender.textproto b/Lib/axisregistry/data/y_transparent_ascender.textproto
index a745ade1d..a14ec03d0 100644
--- a/Lib/axisregistry/data/y_transparent_ascender.textproto
+++ b/Lib/axisregistry/data/y_transparent_ascender.textproto
@@ -10,5 +10,6 @@ fallback {
   value: 750
 }
 fallback_only: false
+illustration_url: "y_transparent_ascender.svg"
 description:
   "A parametric axis for varying the height of lowercase ascenders."
diff --git a/Lib/axisregistry/data/y_transparent_descender.textproto b/Lib/axisregistry/data/y_transparent_descender.textproto
index 072b381f8..a94e84833 100644
--- a/Lib/axisregistry/data/y_transparent_descender.textproto
+++ b/Lib/axisregistry/data/y_transparent_descender.textproto
@@ -10,5 +10,6 @@ fallback {
   value: -250
 }
 fallback_only: false
+illustration_url: "y_transparent_descender.svg"
 description:
   "A parametric axis for varying the height of lowercase descenders."
diff --git a/Lib/axisregistry/data/y_transparent_figures.textproto b/Lib/axisregistry/data/y_transparent_figures.textproto
index 7ac271642..7e8eb94b5 100644
--- a/Lib/axisregistry/data/y_transparent_figures.textproto
+++ b/Lib/axisregistry/data/y_transparent_figures.textproto
@@ -10,5 +10,6 @@ fallback {
   value: 600
 }
 fallback_only: false
+illustration_url: "y_transparent_figures.svg"
 description:
-  "A parametric axis for varying the height of figures."
\ No newline at end of file
+  "A parametric axis for varying the height of figures."
diff --git a/Lib/axisregistry/data/y_transparent_lowercase.textproto b/Lib/axisregistry/data/y_transparent_lowercase.textproto
index 9a4039358..b1bcf945c 100644
--- a/Lib/axisregistry/data/y_transparent_lowercase.textproto
+++ b/Lib/axisregistry/data/y_transparent_lowercase.textproto
@@ -10,5 +10,6 @@ fallback {
   value: 500
 }
 fallback_only: false
+illustration_url: "y_transparent_lowercase.svg"
 description:
   "A parametric axis for varying the height of the lowercase."
diff --git a/Lib/axisregistry/data/y_transparent_uppercase.textproto b/Lib/axisregistry/data/y_transparent_uppercase.textproto
index 74c61242e..f9a182fa8 100644
--- a/Lib/axisregistry/data/y_transparent_uppercase.textproto
+++ b/Lib/axisregistry/data/y_transparent_uppercase.textproto
@@ -10,5 +10,6 @@ fallback {
   value: 725
 }
 fallback_only: false
+illustration_url: "y_transparent_uppercase.svg"
 description:
   "A parametric axis for varying the heights of uppercase letterforms."