diff --git a/src/abr.cpp b/src/abr.cpp
index ebb10a1..8fc01d5 100644
--- a/src/abr.cpp
+++ b/src/abr.cpp
@@ -116,7 +116,7 @@ std::vector<std::shared_ptr<Brush>> ABR::compute_brushes(const std::string& path
         b->m_tip_spacing = samp->value<UnitFloat>("Spcn") * 0.01f;
         b->m_tip_flow = .25f;
         b->m_tip_opacity = 1.f;
-        b->m_tip_angle = glm::radians(samp->value<UnitFloat>("Angl"));
+        b->m_tip_angle = samp->value<UnitFloat>("Angl") / 360.f + 0.5f; // [-180,180] -> [0, 1]
         //b->m_tip_mix = i.m_tip_mix;
         //b->m_tip_stencil = i.m_tip_stencil;
         b->m_tip_wet = p->value<UnitFloat>("Wtdg");
diff --git a/src/app_shaders.cpp b/src/app_shaders.cpp
index 0c967d9..8e514f7 100644
--- a/src/app_shaders.cpp
+++ b/src/app_shaders.cpp
@@ -207,7 +207,7 @@ void App::initShaders()
         "uniform sampler2D tex;\n"
         "uniform sampler2D tex_stroke;\n"
         "uniform sampler2D tex_mask;\n"
-        "uniform sampler2D tex_stencil;\n"
+        //"uniform sampler2D tex_stencil;\n"
         "uniform mediump float alpha;\n"
         "uniform mediump float stroke_alpha;\n"
         "uniform mediump int blend_mode;\n"
diff --git a/src/image.cpp b/src/image.cpp
index 897398b..f098573 100644
--- a/src/image.cpp
+++ b/src/image.cpp
@@ -120,7 +120,7 @@ Image Image::resize_power2() const
     return resize(w, h);
 }
 
-Image Image::resize_squared() const
+Image Image::resize_squared(const glm::u8vec4& bg) const
 {
     Image ret;
     if (width == height)
@@ -146,7 +146,7 @@ Image Image::resize_squared() const
         ret.create(size, size);
         auto ptr_src = reinterpret_cast<glm::u8vec4*>(m_data.get());
         auto ptr_dst = reinterpret_cast<glm::u8vec4*>(ret.m_data.get());
-        std::fill_n(ptr_dst, size * size, glm::u8vec4(0));
+        std::fill_n(ptr_dst, size * size, bg);
         for (int y = 0; y < height; y++)
             std::copy_n(ptr_src + y * width, width, ptr_dst + pad_x + (y + pad_y) * ret.width);
     }
diff --git a/src/image.h b/src/image.h
index 5aa8b00..479f85f 100644
--- a/src/image.h
+++ b/src/image.h
@@ -36,5 +36,5 @@ public:
     void create() { m_data = std::make_unique<uint8_t[]>(size()); }
     Image resize(int w, int h) const;
     Image resize_power2() const;
-    Image resize_squared() const;
+    Image resize_squared(const glm::u8vec4& bg) const;
 };
diff --git a/src/node_panel_brush.cpp b/src/node_panel_brush.cpp
index b7af258..58b81af 100644
--- a/src/node_panel_brush.cpp
+++ b/src/node_panel_brush.cpp
@@ -77,8 +77,10 @@ void NodePanelBrush::init()
                 {
                     std::string path_high = App::I.data_path + "/brushes/" + samp.first + ".png";
                     std::string path_thumb = App::I.data_path + "/brushes/thumbs/" + samp.first + ".png";
-                    samp.second->save(path_high);
-                    auto thumb = samp.second->resize(64, 64);
+                    auto padded = samp.second->resize_squared(glm::u8vec4(255));
+                    auto high = padded.resize_power2();
+                    high.save(path_high);
+                    auto thumb = padded.resize(64, 64);
                     thumb.save(path_thumb);
 
                     async_start();
@@ -123,7 +125,7 @@ void NodePanelBrush::init()
                 std::string path_high = App::I.data_path + "/brushes/" + name + ".png";
                 std::string path_thumb = App::I.data_path + "/brushes/thumbs/" + name + ".png";
 
-                img = img.resize_squared();
+                img = img.resize_squared(glm::u8vec4(255));
                 img.gayscale_alpha();
 
                 auto thumb = img.resize(64, 64);