diff --git a/cws/format.go b/cws/format.go
index 0bdab6c..62d9862 100644
--- a/cws/format.go
+++ b/cws/format.go
@@ -517,7 +517,7 @@ func (cws *CWS) Layer(index int) (layer uv3dp.Layer) {
 		panic(err)
 	}
 
-	layer.Z = float32(index) * cws.properties.Size.LayerHeight
+	layer.Z = cws.properties.LayerZ(index)
 	layer.Image = pngImage.(*image.Gray)
 	layer.Exposure = cws.properties.LayerExposure(index)
 
diff --git a/empty.go b/empty.go
index 4ddba58..57faa35 100644
--- a/empty.go
+++ b/empty.go
@@ -29,7 +29,7 @@ func (empty *EmptyPrintable) Properties() (prop Properties) {
 func (empty *EmptyPrintable) Layer(index int) (layer Layer) {
 	prop := empty.Properties()
 
-	layer.Z = prop.Size.LayerHeight * float32(index)
+	layer.Z = prop.LayerZ(index)
 	layer.Image = image.NewGray(prop.Bounds())
 
 	if index < prop.Bottom.Count {
diff --git a/properties.go b/properties.go
index ad681ab..c42f961 100644
--- a/properties.go
+++ b/properties.go
@@ -6,6 +6,7 @@ package uv3dp
 
 import (
 	"image"
+	"math"
 )
 
 type SizeMillimeter struct {
@@ -118,3 +119,8 @@ func (prop *Properties) LayerExposure(index int) (exposure Exposure) {
 
 	return
 }
+
+// LayerZ get the default Z height at a layer index
+func (prop *Properties) LayerZ(index int) (z float32) {
+	return float32(math.Round(float64(prop.Size.LayerHeight)*float64(index+1)*100) / 100.0)
+}
diff --git a/pws/format.go b/pws/format.go
index 90a89ef..e966714 100644
--- a/pws/format.go
+++ b/pws/format.go
@@ -589,7 +589,7 @@ func (pws *Print) Layer(index int) (layer uv3dp.Layer) {
 		panic(fmt.Sprintf("pws: layer %v/%v: %s", index+1, prop.Size.Layers, err))
 	}
 
-	layer.Z = float32(index) * prop.Size.LayerHeight
+	layer.Z = prop.LayerZ(index)
 	layer.Image = slice
 	return
 }
diff --git a/sl1/format.go b/sl1/format.go
index 3ae305c..648a56f 100644
--- a/sl1/format.go
+++ b/sl1/format.go
@@ -409,7 +409,7 @@ func (sl1 *Sl1) Layer(index int) (layer uv3dp.Layer) {
 		panic(err)
 	}
 
-	layer.Z = float32(index) * sl1.properties.Size.LayerHeight
+	layer.Z = sl1.properties.LayerZ(index)
 	layer.Image = pngImage.(*image.Gray)
 	layer.Exposure = sl1.properties.LayerExposure(index)
 
diff --git a/uvj/format.go b/uvj/format.go
index 4402479..22662ce 100644
--- a/uvj/format.go
+++ b/uvj/format.go
@@ -287,7 +287,7 @@ func (uvj *UVJ) Layer(index int) (layer uv3dp.Layer) {
 
 	if len(uvj.Config.Layers) == 0 {
 		layer = uv3dp.Layer{
-			Z:        float32(index) * uvj.Config.Properties.Size.LayerHeight,
+			Z:        uvj.Config.Properties.LayerZ(index),
 			Exposure: uvj.Config.Properties.LayerExposure(index),
 		}
 	} else {
diff --git a/uvj/format_test.go b/uvj/format_test.go
index e9250e6..d08c3ae 100644
--- a/uvj/format_test.go
+++ b/uvj/format_test.go
@@ -108,7 +108,7 @@ const (
   },
   "Layers": [
     {
-      "Z": 0,
+      "Z": 0.05,
       "Exposure": {
         "LightOnTime": 30.5,
         "LightOffTime": 2.25,
@@ -119,7 +119,7 @@ const (
       }
     },
     {
-      "Z": 0.05,
+      "Z": 0.1,
       "Exposure": {
         "LightOnTime": 30.5,
         "LightOffTime": 2.25,
@@ -130,7 +130,7 @@ const (
       }
     },
     {
-      "Z": 0.1,
+      "Z": 0.15,
       "Exposure": {
         "LightOnTime": 16.5,
         "LightOffTime": 2.25,
@@ -142,7 +142,7 @@ const (
       }
     },
     {
-      "Z": 0.15,
+      "Z": 0.2,
       "Exposure": {
         "LightOnTime": 16.5,
         "LightOffTime": 2.25,
diff --git a/zcodex/format.go b/zcodex/format.go
index 2e1c6cb..ab7d3a7 100644
--- a/zcodex/format.go
+++ b/zcodex/format.go
@@ -418,7 +418,7 @@ func (zcodex *Zcodex) Layer(index int) (layer uv3dp.Layer) {
 		grayImage = asGray(pngImage)
 	}
 
-	layer.Z = float32(index) * zcodex.properties.Size.LayerHeight
+	layer.Z = zcodex.properties.LayerZ(index)
 	layer.Image = grayImage
 	layer.Exposure = zcodex.properties.LayerExposure(index)