diff --git a/data/art/border-bold.png b/data/art/border-bold.png
new file mode 100644
index 000000000..16423a3a7
Binary files /dev/null and b/data/art/border-bold.png differ
diff --git a/docs/dev/Lua API.rst b/docs/dev/Lua API.rst
index 2af9e39f1..e63bc8a61 100644
--- a/docs/dev/Lua API.rst	
+++ b/docs/dev/Lua API.rst	
@@ -4352,11 +4352,22 @@ There are the following predefined frame style tables:
 
   A frame suitable for overlay widget panels.
 
+* ``BOLD_FRAME``
+
+  A frame suitable for a non-draggable panel meant to capture the user's focus,
+  like an important notification, confirmation dialog or error message.
+
 * ``INTERIOR_FRAME``
 
-  A frame suitable for light interior accent elements. This frame does *not* have
-  a visible ``DFHack`` signature on it, so it must not be used as the most external
-  frame for a DFHack-owned UI.
+  A frame suitable for light interior accent elements. This frame does *not*
+  have a visible ``DFHack`` signature on it, so it must not be used as the most
+  external frame for a DFHack-owned UI.
+
+* ``INTERIOR_MEDIUM_FRAME``
+
+  A copy of ``MEDIUM_FRAME`` that lacks the ``DFHack`` signature. Suitable for
+  panels that are part of a larger widget cluster. Must *not* be used as the
+  most external frame for a DFHack-owned UI.
 
 gui.widgets
 ===========
diff --git a/library/LuaApi.cpp b/library/LuaApi.cpp
index c9bdc3021..5573d3f20 100644
--- a/library/LuaApi.cpp
+++ b/library/LuaApi.cpp
@@ -1718,6 +1718,7 @@ static const LuaWrapper::FunctionReg dfhack_textures_module[] = {
     WRAPM(Textures, getControlPanelTexposStart),
     WRAPM(Textures, getThinBordersTexposStart),
     WRAPM(Textures, getMediumBordersTexposStart),
+    WRAPM(Textures, getBoldBordersTexposStart),
     WRAPM(Textures, getPanelBordersTexposStart),
     WRAPM(Textures, getWindowBordersTexposStart),
     { NULL, NULL }
diff --git a/library/include/modules/Textures.h b/library/include/modules/Textures.h
index a438f01f4..95e628d5a 100644
--- a/library/include/modules/Textures.h
+++ b/library/include/modules/Textures.h
@@ -56,6 +56,7 @@ DFHACK_EXPORT long getControlPanelTexposStart();
  */
 DFHACK_EXPORT long getThinBordersTexposStart();
 DFHACK_EXPORT long getMediumBordersTexposStart();
+DFHACK_EXPORT long getBoldBordersTexposStart();
 DFHACK_EXPORT long getPanelBordersTexposStart();
 DFHACK_EXPORT long getWindowBordersTexposStart();
 
diff --git a/library/lua/gui.lua b/library/lua/gui.lua
index 7791f3685..64e203d3c 100644
--- a/library/lua/gui.lua
+++ b/library/lua/gui.lua
@@ -916,8 +916,11 @@ end
 WINDOW_FRAME = make_frame('Window', true)
 PANEL_FRAME = make_frame('Panel', false)
 MEDIUM_FRAME = make_frame('Medium', false)
+BOLD_FRAME = make_frame('Bold', true)
 INTERIOR_FRAME = make_frame('Thin', false)
 INTERIOR_FRAME.signature_pen = false
+INTERIOR_MEDIUM_FRAME = copyall(MEDIUM_FRAME)
+INTERIOR_MEDIUM_FRAME.signature_pen = false
 
 -- for compatibility with pre-steam code
 GREY_LINE_FRAME = WINDOW_FRAME
diff --git a/library/modules/Textures.cpp b/library/modules/Textures.cpp
index 25d44695a..a30f879a0 100644
--- a/library/modules/Textures.cpp
+++ b/library/modules/Textures.cpp
@@ -26,6 +26,7 @@ static long g_on_off_texpos_start = -1;
 static long g_control_panel_texpos_start = -1;
 static long g_thin_borders_texpos_start = -1;
 static long g_medium_borders_texpos_start = -1;
+static long g_bold_borders_texpos_start = -1;
 static long g_panel_borders_texpos_start = -1;
 static long g_window_borders_texpos_start = -1;
 
@@ -134,6 +135,8 @@ void Textures::init(color_ostream &out) {
                                           &g_thin_borders_texpos_start);
     g_num_dfhack_textures += load_textures(out, "hack/data/art/border-medium.png",
                                           &g_medium_borders_texpos_start);
+    g_num_dfhack_textures += load_textures(out, "hack/data/art/border-bold.png",
+                                          &g_bold_borders_texpos_start);
     g_num_dfhack_textures += load_textures(out, "hack/data/art/border-panel.png",
                                           &g_panel_borders_texpos_start);
     g_num_dfhack_textures += load_textures(out, "hack/data/art/border-window.png",
@@ -202,6 +205,10 @@ long Textures::getMediumBordersTexposStart() {
     return g_medium_borders_texpos_start;
 }
 
+long Textures::getBoldBordersTexposStart() {
+    return g_bold_borders_texpos_start;
+}
+
 long Textures::getPanelBordersTexposStart() {
     return g_panel_borders_texpos_start;
 }