diff --git a/src/constants.js b/src/constants.js
index f1ec128..17803b6 100644
--- a/src/constants.js
+++ b/src/constants.js
@@ -2,4 +2,4 @@ export const PRECISION = 0.01;
 export const VERSION = '0.0.18';
 export const LOCAL_STORAGE_KEY = 'PRINTER_SETTINGS';
 export const MIN_AREA = 1; // holes smaller as 1mm2 get removed
-export const Z_OFFSET = 0.15;
+export const Z_OFFSET = 0.3;
diff --git a/src/sliceActions/helpers/GCode.js b/src/sliceActions/helpers/GCode.js
index ea51272..233a5f9 100644
--- a/src/sliceActions/helpers/GCode.js
+++ b/src/sliceActions/helpers/GCode.js
@@ -11,9 +11,8 @@ export const POSITION_Y = 'Y';
 export const POSITION_Z = 'Z';
 
 export default class {
-  constructor(nozzleToFilamentRatio) {
-    this._nozzleToFilamentRatio = nozzleToFilamentRatio;
-
+  constructor(layerHeight) {
+    this._nozzleToFilamentRatio = 1;
     this._gcode = [`; Generated with Doodle3D Slicer V${VERSION}`];
     this._currentValues = {};
     this._nozzlePosition = new THREE.Vector2(0, 0);
@@ -27,6 +26,12 @@ export default class {
     this._gcode.push(command);
   }
 
+  updateLayerHeight(layerHeight, nozzleDiameter, filamentThickness) {
+    const filamentSurfaceArea = Math.pow((filamentThickness / 2), 2) * Math.PI;
+    const lineSurfaceArea = nozzleDiameter * layerHeight;
+    this._nozzleToFilamentRatio = lineSurfaceArea / filamentSurfaceArea;
+  }
+
   turnFanOn(fanSpeed) {
     this._isFanOn = true;
 
diff --git a/src/sliceActions/slicesToGCode.js b/src/sliceActions/slicesToGCode.js
index e794499..1b7aa98 100644
--- a/src/sliceActions/slicesToGCode.js
+++ b/src/sliceActions/slicesToGCode.js
@@ -15,11 +15,8 @@ export default function slicesToGCode(slices, settings) {
     combing
   } = settings;
 
-  const filamentSurfaceArea = Math.pow((filamentThickness / 2), 2) * Math.PI;
-  const lineSurfaceArea = nozzleDiameter * layerHeight;
-  const nozzleToFilamentRatio = lineSurfaceArea / filamentSurfaceArea;
-
-  const gcode = new GCode(nozzleToFilamentRatio);
+  const gcode = new GCode();
+  gcode.updateLayerHeight(Z_OFFSET, nozzleDiameter, filamentThickness)
 
   if (settings.startCode) gcode.addGCode(settings.startCode, settings);
 
@@ -34,6 +31,7 @@ export default function slicesToGCode(slices, settings) {
     const z = layer * layerHeight + Z_OFFSET;
 
     if (layer === 1) {
+      gcode.updateLayerHeight(layerHeight, nozzleDiameter, filamentThickness);
       gcode.turnFanOn();
       isFirstLayer = false;
     }