diff --git a/data/layout.xml b/data/layout.xml
index c5e9108..8c9ecee 100644
--- a/data/layout.xml
+++ b/data/layout.xml
@@ -1634,6 +1634,9 @@ Here's a list of what's available in this release.
           <border id="ext-fbf" height="20" width="30" color="0 0 0 1" align="center" justify="center" margin="0 5 0 0">
             <text id="txt-rec" text="FbF" color="0 0 0 1"/>
           </border>
+          <border id="ext-dpi" height="20" width="50" color=".2" align="center" justify="center" margin="0 5 0 0">
+            <text id="txt-dpi" text="4x-dpi" color="1"/>
+          </border>
         </node>
       </border>
       <!-- toolbar -->
diff --git a/src/app_layout.cpp b/src/app_layout.cpp
index 653fdfa..bd817ef 100644
--- a/src/app_layout.cpp
+++ b/src/app_layout.cpp
@@ -14,6 +14,8 @@ void App::title_update()
     snprintf(str, 256, "Panodoc: %s%s (%s)", doc_name.c_str(), canvas->m_canvas->m_unsaved ? "*" : "", res_to_string(canvas->m_canvas->m_width).c_str());
     if (auto docname = layout[main_id]->find<NodeText>("txt-docname"))
         docname->set_text(str);
+    if (auto node = layout[main_id]->find<NodeText>("txt-dpi"))
+        node->set_text(fmt::format("{}x-dpi", zoom).c_str());
 }
 
 void App::init_toolbar_main()
diff --git a/src/node_canvas.cpp b/src/node_canvas.cpp
index 93aba51..14a1a83 100644
--- a/src/node_canvas.cpp
+++ b/src/node_canvas.cpp
@@ -107,14 +107,25 @@ void NodeCanvas::draw()
         m_canvas->m_plane_shape[plane_index] = m_canvas->face_to_shape2D(plane_index);
     }
 
+
+    if (zoom > 1.f)
+    {
+        m_rtt.bindFramebuffer();
+        glClearColor(1, 1, 1, 0);
+        glClear(GL_COLOR_BUFFER_BIT);
+        glViewport(0, 0, m_rtt.getWidth(), m_rtt.getHeight());
+    }
+    else
+    {
+        glClearColor(1, 1, 1, 0);
+        glClear(GL_COLOR_BUFFER_BIT);
+        glViewport(c.x + App::I.off_x, c.y + App::I.off_y, c.z, c.w);
+    }
+
+    // NOTE: draw_merge has been disabled for worst performance
     bool draw_merged = !(m_canvas->m_current_mode == kCanvasMode::Camera);
     draw_merged = false;
 
-    m_rtt.bindFramebuffer();
-    glClearColor(1, 1, 1, 0);
-    glClear(GL_COLOR_BUFFER_BIT);
-    glViewport(0, 0, m_rtt.getWidth(), m_rtt.getHeight());
-
     if (draw_merged)
     {
         glDisable(GL_BLEND);
@@ -404,18 +415,18 @@ void NodeCanvas::draw()
             glEnable(GL_BLEND);
         
             //draw the grid
-            //for (int plane_index = 0; plane_index < 6; plane_index++)
-            //{
-            //    auto plane_mvp = proj * camera *
-            //        glm::scale(glm::vec3(m_canvas->m_order.size() + 500.f)) *
-            //        m_canvas->m_plane_transform[plane_index] *
-            //        glm::translate(glm::vec3(0, 0, -1.f));
+            for (int plane_index = 0; plane_index < 6; plane_index++)
+            {
+                auto plane_mvp = proj * camera *
+                    glm::scale(glm::vec3(m_canvas->m_order.size() + 500.f)) *
+                    m_canvas->m_plane_transform[plane_index] *
+                    glm::translate(glm::vec3(0, 0, -1.f));
 
-            //    ShaderManager::use(kShader::Checkerboard);
-            //    ShaderManager::u_int(kShaderUniform::Colorize, false);
-            //    ShaderManager::u_mat4(kShaderUniform::MVP, plane_mvp);
-            //    m_face_plane.draw_fill();
-            //}
+                ShaderManager::use(kShader::Checkerboard);
+                ShaderManager::u_int(kShaderUniform::Colorize, false);
+                ShaderManager::u_mat4(kShaderUniform::MVP, plane_mvp);
+                m_face_plane.draw_fill();
+            }
 
             // draw the layers
             m_sampler.bind(0);
@@ -429,21 +440,24 @@ void NodeCanvas::draw()
         }
     }
 
-    m_rtt.unbindFramebuffer();
+    if (zoom > 1.f)
+    {
+        m_rtt.unbindFramebuffer();
 
-    glClearColor(1, 1, 1, 0);
-    glClear(GL_COLOR_BUFFER_BIT);
-    glViewport(c.x + App::I.off_x, c.y + App::I.off_y, c.z, c.w);
+        glClearColor(1, 1, 1, 0);
+        glClear(GL_COLOR_BUFFER_BIT);
+        glViewport(c.x + App::I.off_x, c.y + App::I.off_y, c.z, c.w);
 
-    // draw the canvas
-    m_sampler_linear.bind(0);
-    glActiveTexture(GL_TEXTURE0);
-    m_rtt.bindTexture();
-    ShaderManager::use(kShader::Texture);
-    ShaderManager::u_int(kShaderUniform::Tex, 0);
-    ShaderManager::u_mat4(kShaderUniform::MVP, glm::ortho<float>(-1, 1, -1, 1));
-    m_face_plane.draw_fill();
-    m_rtt.unbindTexture();
+        // draw the canvas
+        m_sampler_linear.bind(0);
+        glActiveTexture(GL_TEXTURE0);
+        m_rtt.bindTexture();
+        ShaderManager::use(kShader::Texture);
+        ShaderManager::u_int(kShaderUniform::Tex, 0);
+        ShaderManager::u_mat4(kShaderUniform::MVP, glm::ortho<float>(-1, 1, -1, 1));
+        m_face_plane.draw_fill();
+        m_rtt.unbindTexture();
+    }
 
 
     glDisable(GL_DEPTH_TEST);