diff --git a/Sources/arm/Layers.hx b/Sources/arm/Layers.hx
index d9f0e786..110630a5 100644
--- a/Sources/arm/Layers.hx
+++ b/Sources/arm/Layers.hx
@@ -84,13 +84,23 @@ class Layers {
 	public static function resizeLayers(g:kha.graphics4.Graphics) {
 		var C = UITrait.inst.C;
 		if (UITrait.inst.resHandle.position >= 4) { // Save memory for >=16k
-			C.undo_steps = 0;// No undo for 16k+
+			C.undo_steps = 1;
 			if (UITrait.inst.undoHandle != null) UITrait.inst.undoHandle.value = C.undo_steps;
 			while (UITrait.inst.undoLayers.length > C.undo_steps) { var l = UITrait.inst.undoLayers.pop(); l.unload(); }
 		}
 		g.end();
 		for (l in UITrait.inst.layers) resizeLayer(l);
 		for (l in UITrait.inst.undoLayers) resizeLayer(l);
+		var rts = RenderPath.active.renderTargets;
+		rts.get("texpaint_mask0").image.unload();
+		rts.get("texpaint_mask0").raw.width = Config.getTextureRes();
+		rts.get("texpaint_mask0").raw.height = Config.getTextureRes();
+		rts.get("texpaint_mask0").image = kha.Image.createRenderTarget(Config.getTextureRes(), Config.getTextureRes(), kha.graphics4.TextureFormat.L8, kha.graphics4.DepthStencilFormat.NoDepthAndStencil);
+		rts.get("texpaint_mask1").image.unload();
+		rts.get("texpaint_mask1").raw.width = Config.getTextureRes();
+		rts.get("texpaint_mask1").raw.height = Config.getTextureRes();
+		rts.get("texpaint_mask1").image = kha.Image.createRenderTarget(Config.getTextureRes(), Config.getTextureRes(), kha.graphics4.TextureFormat.L8, kha.graphics4.DepthStencilFormat.NoDepthAndStencil);
+		UITrait.inst.maskDirty = true;
 		g.begin();
 		UITrait.inst.ddirty = 2;
 		iron.App.removeRender(resizeLayers);
diff --git a/Sources/arm/Uniforms.hx b/Sources/arm/Uniforms.hx
index e408a27e..0ac8cd30 100644
--- a/Sources/arm/Uniforms.hx
+++ b/Sources/arm/Uniforms.hx
@@ -116,7 +116,6 @@ class Uniforms {
 			return UITrait.inst.decalMaskImage;
 		}
 		else if (link == "_texpaint_undo") {
-			// if (UITrait.inst.pushUndo && UITrait.inst.C.undo_steps > 0)
 			var i = UITrait.inst.undoI - 1 < 0 ? UITrait.inst.C.undo_steps - 1 : UITrait.inst.undoI - 1;
 			return iron.RenderPath.active.renderTargets.get("texpaint_undo" + i).image;
 		}
diff --git a/Sources/arm/renderpath/RenderPathDeferred.hx b/Sources/arm/renderpath/RenderPathDeferred.hx
index 0e375c40..1d926407 100644
--- a/Sources/arm/renderpath/RenderPathDeferred.hx
+++ b/Sources/arm/renderpath/RenderPathDeferred.hx
@@ -161,7 +161,7 @@ class RenderPathDeferred {
 
 		var tid = UITrait.inst.selectedLayer.id;
 
-		if (UITrait.inst.pushUndo && UITrait.inst.C.undo_steps > 0) {
+		if (UITrait.inst.pushUndo) {
 			var i = UITrait.inst.undoI;
 			path.setTarget("texpaint_undo" + i, ["texpaint_nor_undo" + i, "texpaint_pack_undo" + i]);			
 			path.bindTarget("texpaint" + tid, "tex0");
diff --git a/Sources/arm/ui/UITrait.hx b/Sources/arm/ui/UITrait.hx
index 14b92c34..1887845c 100644
--- a/Sources/arm/ui/UITrait.hx
+++ b/Sources/arm/ui/UITrait.hx
@@ -608,7 +608,7 @@ class UITrait extends iron.Trait {
 	}
 
 	public function doUndo() {
-		if (undos > 0 && C.undo_steps > 0) {
+		if (undos > 0) {
 			undoI = undoI - 1 < 0 ? C.undo_steps - 1 : undoI - 1;
 			var lay = undoLayers[undoI];
 			var opos = paintObjects.indexOf(lay.targetObject);
@@ -626,7 +626,7 @@ class UITrait extends iron.Trait {
 	}
 
 	public function doRedo() {
-		if (redos > 0 && C.undo_steps > 0) {
+		if (redos > 0) {
 			var lay = undoLayers[undoI];
 			var opos = paintObjects.indexOf(lay.targetObject);
 			var lpos = layers.indexOf(lay.targetLayer);
@@ -665,7 +665,7 @@ class UITrait extends iron.Trait {
 					cloneStartY = mouse.y;
 				}
 				else {
-					if (brushTime == 0 && C.undo_steps > 0) { // Paint started
+					if (brushTime == 0) { // Paint started
 						pushUndo = true;
 						if (projectPath != "") {
 							kha.Window.get(0).title = arm.App.filenameHandle.text + "* - ArmorPaint";
@@ -2224,7 +2224,7 @@ class UITrait extends iron.Trait {
 				ui.separator();
 				if (ui.panel(Id.handle({selected: true}), "Usage", 1)) {
 					undoHandle = Id.handle({value: C.undo_steps});
-					C.undo_steps = Std.int(ui.slider(undoHandle, "Undo Steps", 0, 64, false, 1));
+					C.undo_steps = Std.int(ui.slider(undoHandle, "Undo Steps", 1, 64, false, 1));
 					if (undoHandle.changed) {
 						ui.g.end();
 						while (undoLayers.length < C.undo_steps) undoLayers.push(new LayerSlot("_undo" + undoLayers.length));