diff --git a/src/kiri/app/api.js b/src/kiri/app/api.js
index d7520350..360775cd 100644
--- a/src/kiri/app/api.js
+++ b/src/kiri/app/api.js
@@ -76,7 +76,7 @@ function isSecure(proto) {
  * @param {string} filename - Filename for download
  */
 function download(data, filename) {
-    let url = WIN.URL.createObjectURL(new Blob([data], {type: "octet/stream"}));
+    let url = window.URL.createObjectURL(new Blob([data], {type: "octet/stream"}));
     $('mod-any').innerHTML = `<a id="_dexport_" href="${url}" download="${filename}">x</a>`;
     $('_dexport_').click();
 }
diff --git a/src/kiri/app/export.js b/src/kiri/app/export.js
index a44b7f0d..4e44302d 100644
--- a/src/kiri/app/export.js
+++ b/src/kiri/app/export.js
@@ -136,9 +136,9 @@ function exportLaserDialog(data, names) {
     const driver = laser_driver;
     const { process } = settings;
     if (process.ctOutStack) {
-        $('print-stl').classList.remove('hide');
+        $('print-obj').classList.remove('hide');
     } else {
-        $('print-stl').classList.add('hide');
+        $('print-obj').classList.add('hide');
     }
 
     function download_svg() {
@@ -155,10 +155,10 @@ function exportLaserDialog(data, names) {
         );
     }
 
-    function download_stl() {
+    function download_obj() {
         api.util.download(
-            driver.exportSTL(settings, data),
-            $('print-filename-laser').value + ".stl"
+            driver.exportOBJ(settings, data),
+            $('print-filename-laser').value + ".obj"
         );
     }
 
@@ -178,7 +178,7 @@ function exportLaserDialog(data, names) {
     $('print-lines').value = util.comma(segments);
     $('print-svg').onclick = download_svg;
     $('print-dxf').onclick = download_dxf;
-    $('print-stl').onclick = download_stl;
+    $('print-obj').onclick = download_obj;
     $('print-lg').onclick = download_gcode;
 }
 
diff --git a/src/kiri/mode/laser/driver.js b/src/kiri/mode/laser/driver.js
index bbd7f60f..c097bfa4 100644
--- a/src/kiri/mode/laser/driver.js
+++ b/src/kiri/mode/laser/driver.js
@@ -11,7 +11,7 @@ import { render } from '../../core/render.js';
 import { slicer } from '../../../geo/slicer.js';
 import { newSlice } from '../../core/slice.js';
 import { newPolygon } from '../../../geo/polygon.js';
-import { STL } from '../../../load/stl.js';
+import { encode as encodeOBJ } from '../../../load/obj.js';
 
 export const TYPE = {
     LASER: 0,
@@ -610,7 +610,7 @@ function exportElements(settings, output, onpre, onpoly, onpost, onpoint, onlaye
     onpost();
 };
 
-function exportSTL(settings, data) {
+function exportOBJ(settings, data) {
     let { ctSliceHeight, ctOutSmooth } = settings.process;
     let polys = [];
     for (let array of data) {
@@ -633,7 +633,7 @@ function exportSTL(settings, data) {
         }).flat().filter(v => v);
     }
     let layers = {};
-    let mesh = [];
+    let obj = [];
     for (let poly of polys) {
         let z = poly.getZ();
         let layer = layers[z];
@@ -644,13 +644,15 @@ function exportSTL(settings, data) {
     }
     for (let rec of Object.entries(layers)) {
         let [ z, polys ] = rec;
+        let layer = [];
         polys = POLY.nest(polys);
         for (let poly of polys) {
             let ext = poly.setZ(0).extrude(ctSliceHeight, { zadd: parseFloat(z) });
-            mesh = mesh.concat(ext);
+            layer = layer.concat(ext);
         }
+        obj.push({ file:`z-${z}`, varr: layer });
     }
-    return new STL().encode(mesh);
+    return encodeOBJ(obj);
 }
 
 /**
@@ -933,5 +935,5 @@ export const LASER = {
     exportGCode,
     exportDXF,
     exportSVG,
-    exportSTL
+    exportOBJ
 };
diff --git a/web/kiri/index.html b/web/kiri/index.html
index ae9e1a88..523b86e9 100644
--- a/web/kiri/index.html
+++ b/web/kiri/index.html
@@ -716,7 +716,7 @@
             <div class="f-row box">
                 <button id="print-svg" class="grow">svg</button>
                 <button id="print-dxf" class="grow">dxf</button>
-                <button id="print-stl" class="grow">stl</button>
+                <button id="print-obj" class="grow">obj</button>
                 <button id="print-lg" class="grow">gcode</button>
             </div>
         </div>