diff --git a/pd/nw/pdgui.js b/pd/nw/pdgui.js
index e62f16b4b7289bf155945b1cda8e8c471ba3015d..20cd3248de1dbbd63821ecc8d5419edb26018a04 100644
--- a/pd/nw/pdgui.js
+++ b/pd/nw/pdgui.js
@@ -1246,14 +1246,50 @@ function menu_send(name) {
     }
 }
 
+/*
+ico@vt.edu 20200907: added svg tiled background to reflect edit mode and
+integrated it into the canvas_set_editmode below.
+
+LATER: consider adding an interim version that reflects only the ctrl button press
+*/
+var gui_editmode_svg_background = "url(\"data:image/svg+xml,%3Csvg " +
+        "xmlns='http://www.w3.org/2000/svg' width='100' height='100' viewBox='0 0 " +
+        " 100 100'%3E%3Cg fill-rule='evenodd'%3E%3Cg fill='%239C92AC' fill-opacity" +
+        "='0.4'%3E%3Cpath opacity='.5' d='M96 95h4v1h-4v4h-1v-4h-9v4h-1v-4h-9v4h-1" +
+        "v-4h-9v4h-1v-4h-9v4h-1v-4h-9v4h-1v-4h-9v4h-1v-4h-9v4h-1v-4h-9v4h-1v-4H0v-" +
+        "1h15v-9H0v-1h15v-9H0v-1h15v-9H0v-1h15v-9H0v-1h15v-9H0v-1h15v-9H0v-1h15v-9" +
+        "H0v-1h15v-9H0v-1h15V0h1v15h9V0h1v15h9V0h1v15h9V0h1v15h9V0h1v15h9V0h1v15h9" +
+        "V0h1v15h9V0h1v15h9V0h1v15h4v1h-4v9h4v1h-4v9h4v1h-4v9h4v1h-4v9h4v1h-4v9h4v" +
+        "1h-4v9h4v1h-4v9h4v1h-4v9zm-1 0v-9h-9v9h9zm-10 0v-9h-9v9h9zm-10 0v-9h-9v9h" +
+        "9zm-10 0v-9h-9v9h9zm-10 0v-9h-9v9h9zm-10 0v-9h-9v9h9zm-10 0v-9h-9v9h9zm-1" +
+        "0 0v-9h-9v9h9zm-9-10h9v-9h-9v9zm10 0h9v-9h-9v9zm10 0h9v-9h-9v9zm10 0h9v-9" +
+        "h-9v9zm10 0h9v-9h-9v9zm10 0h9v-9h-9v9zm10 0h9v-9h-9v9zm10 0h9v-9h-9v9zm9-" +
+        "10v-9h-9v9h9zm-10 0v-9h-9v9h9zm-10 0v-9h-9v9h9zm-10 0v-9h-9v9h9zm-10 0v-9" +
+        "h-9v9h9zm-10 0v-9h-9v9h9zm-10 0v-9h-9v9h9zm-10 0v-9h-9v9h9zm-9-10h9v-9h-9" +
+        "v9zm10 0h9v-9h-9v9zm10 0h9v-9h-9v9zm10 0h9v-9h-9v9zm10 0h9v-9h-9v9zm10 0h" +
+        "9v-9h-9v9zm10 0h9v-9h-9v9zm10 0h9v-9h-9v9zm9-10v-9h-9v9h9zm-10 0v-9h-9v9h" +
+        "9zm-10 0v-9h-9v9h9zm-10 0v-9h-9v9h9zm-10 0v-9h-9v9h9zm-10 0v-9h-9v9h9zm-1" +
+        "0 0v-9h-9v9h9zm-10 0v-9h-9v9h9zm-9-10h9v-9h-9v9zm10 0h9v-9h-9v9zm10 0h9v-" +
+        "9h-9v9zm10 0h9v-9h-9v9zm10 0h9v-9h-9v9zm10 0h9v-9h-9v9zm10 0h9v-9h-9v9zm1" +
+        "0 0h9v-9h-9v9zm9-10v-9h-9v9h9zm-10 0v-9h-9v9h9zm-10 0v-9h-9v9h9zm-10 0v-9" +
+        "h-9v9h9zm-10 0v-9h-9v9h9zm-10 0v-9h-9v9h9zm-10 0v-9h-9v9h9zm-10 0v-9h-9v9" +
+        "h9zm-9-10h9v-9h-9v9zm10 0h9v-9h-9v9zm10 0h9v-9h-9v9zm10 0h9v-9h-9v9zm10 0" +
+        "h9v-9h-9v9zm10 0h9v-9h-9v9zm10 0h9v-9h-9v9zm10 0h9v-9h-9v9z'/%3E%3Cpath d" +
+        "='M6 5V0H5v5H0v1h5v94h1V6h94V5H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E\")";
+
 // requires nw.js API (Menuitem)
 function canvas_set_editmode(cid, state) {
     gui(cid).get_elem("patchsvg", function(patchsvg, w) {
         w.set_editmode_checkbox(state !== 0 ? true : false);
         if (state !== 0) {
             patchsvg.classList.add("editmode");
+            //post("editmode:" + gui_editmode_svg_background);
+            patchwin[cid].window.document.body.style.setProperty("background-image",
+                gui_editmode_svg_background);
         } else {
             patchsvg.classList.remove("editmode");
+            patchwin[cid].window.document.body.style.setProperty("background-image",
+                "none");  
         }
     });
 }