diff --git a/src/lib/make-toolbox-xml.js b/src/lib/make-toolbox-xml.js
index 59787f486..0c25b7095 100644
--- a/src/lib/make-toolbox-xml.js
+++ b/src/lib/make-toolbox-xml.js
@@ -1,4 +1,6 @@
-const separator = '<sep gap="45"/>';
+const categorySeparator = '<sep gap="36"/>';
+
+const blockSeparator = '<sep gap="36"/>'; // At default scale, about 28px
 
 const motion = `
     <category name="Motion" colour="#4C97FF" secondaryColour="#3373CC">
@@ -23,6 +25,7 @@ const motion = `
                 </shadow>
             </value>
         </block>
+        ${blockSeparator}
         <block type="motion_pointindirection">
             <value name="DIRECTION">
                 <shadow type="math_angle">
@@ -36,6 +39,7 @@ const motion = `
                 </shadow>
             </value>
         </block>
+        ${blockSeparator}
         <block type="motion_gotoxy">
             <value name="X">
                 <shadow id="movex" type="math_number">
@@ -82,6 +86,7 @@ const motion = `
                 </shadow>
             </value>
         </block>
+        ${blockSeparator}
         <block type="motion_changexby">
             <value name="DX">
                 <shadow type="math_number">
@@ -110,11 +115,15 @@ const motion = `
                 </shadow>
             </value>
         </block>
+        ${blockSeparator}
         <block type="motion_ifonedgebounce"/>
+        ${blockSeparator}
         <block type="motion_setrotationstyle"/>
+        ${blockSeparator}
         <block id="xposition" type="motion_xposition"/>
         <block id="yposition" type="motion_yposition"/>
         <block id="direction" type="motion_direction"/>
+        ${categorySeparator}
     </category>
 `;
 
@@ -158,8 +167,10 @@ const looks = `
                 </shadow>
             </value>
         </block>
+        ${blockSeparator}
         <block type="looks_show"/>
         <block type="looks_hide"/>
+        ${blockSeparator}
         <block type="looks_switchcostumeto">
             <value name="COSTUME">
                 <shadow type="looks_costume"/>
@@ -177,6 +188,7 @@ const looks = `
                 <shadow type="looks_backdrops"/>
             </value>
         </block>
+        ${blockSeparator}
         <block type="looks_changeeffectby">
             <value name="CHANGE">
                 <shadow type="math_number">
@@ -192,6 +204,7 @@ const looks = `
             </value>
         </block>
         <block type="looks_cleargraphiceffects"/>
+        ${blockSeparator}
         <block type="looks_changesizeby">
             <value name="CHANGE">
                 <shadow type="math_number">
@@ -206,6 +219,7 @@ const looks = `
                 </shadow>
             </value>
         </block>
+        ${blockSeparator}
         <block type="looks_gotofront"/>
         <block type="looks_gobacklayers">
             <value name="NUM">
@@ -214,10 +228,12 @@ const looks = `
                 </shadow>
             </value>
         </block>
+        ${blockSeparator}
         <block id="costumeorder" type="looks_costumeorder"/>
         <block id="backdroporder" type="looks_backdroporder"/>
         <block id="backdropname" type="looks_backdropname"/>
         <block id="size" type="looks_size"/>
+        ${categorySeparator}
     </category>
 `;
 
@@ -234,6 +250,7 @@ const sound = `
             </value>
         </block>
         <block type="sound_stopallsounds"/>
+        ${blockSeparator}
         <block type="sound_playdrumforbeats">
             <value name="DRUM">
                 <shadow type="sound_drums_menu"/>
@@ -251,6 +268,7 @@ const sound = `
                 </shadow>
             </value>
         </block>
+        ${blockSeparator}
         <block type="sound_playnoteforbeats">
             <value name="NOTE">
                 <shadow type="math_number">
@@ -268,6 +286,7 @@ const sound = `
                 <shadow type="sound_instruments_menu"/>
             </value>
         </block>
+        ${blockSeparator}
         <block type="sound_changeeffectby">
             <value name="VALUE">
                 <shadow type="math_number">
@@ -283,6 +302,7 @@ const sound = `
             </value>
         </block>
         <block type="sound_cleareffects"/>
+        ${blockSeparator}
         <block type="sound_changevolumeby">
             <value name="VOLUME">
                 <shadow type="math_number">
@@ -298,6 +318,7 @@ const sound = `
             </value>
         </block>
         <block id="volume" type="sound_volume"/>
+        ${blockSeparator}
         <block type="sound_changetempoby">
             <value name="TEMPO">
                 <shadow type="math_number">
@@ -313,6 +334,7 @@ const sound = `
             </value>
         </block>
         <block id="tempo" type="sound_tempo"/>
+        ${categorySeparator}
     </category>
 `;
 
@@ -324,6 +346,7 @@ const events = `
         <block type="event_whenthisspriteclicked"/>
         <block type="event_whenbackdropswitchesto">
         </block>
+        ${blockSeparator}
         <block type="event_whengreaterthan">
             <value name="VALUE">
                 <shadow type="math_number">
@@ -331,6 +354,7 @@ const events = `
                 </shadow>
             </value>
         </block>
+        ${blockSeparator}
         <block type="event_whenbroadcastreceived">
         </block>
         <block type="event_broadcast">
@@ -343,6 +367,7 @@ const events = `
                 <shadow type="event_broadcast_menu"/>
             </value>
         </block>
+        ${categorySeparator}
     </category>
 `;
 
@@ -355,6 +380,7 @@ const control = `
                 </shadow>
             </value>
         </block>
+        ${blockSeparator}
         <block type="control_repeat">
             <value name="TIMES">
                 <shadow type="math_whole_number">
@@ -363,11 +389,14 @@ const control = `
             </value>
         </block>
         <block type="control_forever"/>
+        ${blockSeparator}
         <block type="control_if"/>
         <block type="control_if_else"/>
         <block type="control_wait_until"/>
         <block type="control_repeat_until"/>
+        ${blockSeparator}
         <block type="control_stop"/>
+        ${blockSeparator}
         <block type="control_start_as_clone"/>
         <block type="control_create_clone_of">
             <value name="CLONE_OPTION">
@@ -375,6 +404,7 @@ const control = `
             </value>
         </block>
         <block type="control_delete_this_clone"/>
+        ${categorySeparator}
     </category>
 `;
 
@@ -403,6 +433,7 @@ const sensing = `
                 <shadow type="sensing_distancetomenu"/>
             </value>
         </block>
+        ${blockSeparator}
         <block type="sensing_keypressed">
             <value name="KEY_OPTION">
                 <shadow type="sensing_keyoptions"/>
@@ -411,9 +442,12 @@ const sensing = `
         <block type="sensing_mousedown"/>
         <block type="sensing_mousex"/>
         <block type="sensing_mousey"/>
+        ${blockSeparator}
         <block id="loudness" type="sensing_loudness"/>
+        ${blockSeparator}
         <block id="timer" type="sensing_timer"/>
         <block type="sensing_resettimer"/>
+        ${blockSeparator}
         <block id="of" type="sensing_of">
             <value name="PROPERTY">
                 <shadow id="sensing_of_property_menu" type="sensing_of_property_menu"/>
@@ -422,12 +456,14 @@ const sensing = `
                 <shadow id="sensing_of_object_menu" type="sensing_of_object_menu"/>
             </value>
         </block>
+        ${blockSeparator}
         <block id="current" type="sensing_current">
             <value name="CURRENTMENU">
                 <shadow id="sensing_currentmenu" type="sensing_currentmenu"/>
             </value>
         </block>
         <block type="sensing_dayssince2000"/>
+        ${categorySeparator}
     </category>
 `;
 
@@ -481,6 +517,7 @@ const operators = `
                 </shadow>
             </value>
         </block>
+        ${blockSeparator}
         <block type="operator_random">
             <value name="FROM">
                 <shadow type="math_number">
@@ -493,6 +530,7 @@ const operators = `
                 </shadow>
             </value>
         </block>
+        ${blockSeparator}
         <block type="operator_lt">
             <value name="OPERAND1">
                 <shadow type="text">
@@ -529,9 +567,11 @@ const operators = `
                 </shadow>
             </value>
         </block>
+        ${blockSeparator}
         <block type="operator_and"/>
         <block type="operator_or"/>
         <block type="operator_not"/>
+        ${blockSeparator}
         <block type="operator_join">
             <value name="STRING1">
                 <shadow type="text">
@@ -563,6 +603,7 @@ const operators = `
                 </shadow>
             </value>
         </block>
+        ${blockSeparator}
         <block type="operator_mod">
             <value name="NUM1">
                 <shadow type="math_number">
@@ -582,6 +623,7 @@ const operators = `
                 </shadow>
             </value>
         </block>
+        ${blockSeparator}
         <block type="operator_mathop">
             <value name="NUM">
                 <shadow type="math_number">
@@ -589,6 +631,7 @@ const operators = `
                 </shadow>
             </value>
         </block>
+        ${categorySeparator}
     </category>
 `;
 
@@ -605,7 +648,7 @@ const xmlClose = '</xml>';
  * @returns {string} - a ScratchBlocks-style XML document for the contents of the toolbox.
  */
 const makeToolboxXML = function (categoriesXML) {
-    const gap = [separator];
+    const gap = [categorySeparator];
 
     const everything = [
         xmlOpen,
@@ -624,7 +667,6 @@ const makeToolboxXML = function (categoriesXML) {
     }
 
     everything.push(xmlClose);
-
     return everything.join('\n');
 };