diff --git a/src/kiri/stack.js b/src/kiri/stack.js
index 73f0b3dd..62b2286b 100644
--- a/src/kiri/stack.js
+++ b/src/kiri/stack.js
@@ -5,12 +5,12 @@
 (function() {
 
     class Stack {
-        constructor(view) {
+        constructor(view, freeMem) {
             this._view = view;
             this.view = view.newGroup();
             this.slices = [];
             this.meshes = [];
-            this.freeMem = true;
+            this.freeMem = freeMem;
         }
 
         size() {
@@ -36,6 +36,10 @@
             this.view = this.slices = this.meshes = null;
         }
 
+        setFreeMem(bool) {
+            this.freeMem = bool;
+        }
+
         setVisible(newMin, newMax) {
             this.show();
             for (let i=0, s=this.slices, len=s.length; i<len; i++) {
diff --git a/src/kiri/stacks.js b/src/kiri/stacks.js
index 0d90d8ee..9a281255 100644
--- a/src/kiri/stacks.js
+++ b/src/kiri/stacks.js
@@ -5,8 +5,8 @@
 (function() {
 
     let KIRI = self.kiri,
-        stacks = {},
         freeMem = true,
+        stacks = {},
         tallest = 0,
         min = 0,
         max = 0,
@@ -20,6 +20,7 @@
     }
 
     function setFreeMem(bool) {
+        Object.values(stacks).forEach(stack => stack.obj.setFreeMem(bool));
         freeMem = bool;
         return this;
     }
@@ -57,7 +58,7 @@
         }
         const stack = stacks[name] = {
             layers: [ ],
-            obj: new KIRI.Stack(view),
+            obj: new KIRI.Stack(view, freeMem),
             add: function(layers) {
                 let map = stack.obj.addLayers(layers);
                 for (const [label, mats] of Object.entries(map)) {