diff --git a/colormatrix.go b/colormatrix.go
index 249354e2f..7ee0e8178 100644
--- a/colormatrix.go
+++ b/colormatrix.go
@@ -21,6 +21,16 @@ import (
 // ColorMDim is a dimension of a ColorM.
 const ColorMDim = 5
 
+var colorMI = ColorM{
+	initialized: true,
+	es: [ColorMDim - 1][ColorMDim]float64{
+		{1, 0, 0, 0, 0},
+		{0, 1, 0, 0, 0},
+		{0, 0, 1, 0, 0},
+		{0, 0, 0, 1, 0},
+	},
+}
+
 // A ColorM represents a matrix to transform coloring when rendering an image.
 //
 // A ColorM is applied to the source alpha color
@@ -34,15 +44,6 @@ type ColorM struct {
 	es          [ColorMDim - 1][ColorMDim]float64
 }
 
-func colorMatrixEsI() [ColorMDim - 1][ColorMDim]float64 {
-	return [ColorMDim - 1][ColorMDim]float64{
-		{1, 0, 0, 0, 0},
-		{0, 1, 0, 0, 0},
-		{0, 0, 1, 0, 0},
-		{0, 0, 0, 1, 0},
-	}
-}
-
 func (c ColorM) dim() int {
 	return ColorMDim
 }
@@ -62,8 +63,7 @@ func (c ColorM) Element(i, j int) float64 {
 // This returns c.
 func (c *ColorM) Concat(other ColorM) ColorM {
 	if !c.initialized {
-		c.es = colorMatrixEsI()
-		c.initialized = true
+		*c = colorMI
 	}
 	result := ColorM{}
 	mul(&other, c, &result)
@@ -75,8 +75,7 @@ func (c *ColorM) Concat(other ColorM) ColorM {
 // This returns c.
 func (c *ColorM) Add(other ColorM) ColorM {
 	if !c.initialized {
-		c.es = colorMatrixEsI()
-		c.initialized = true
+		*c = colorMI
 	}
 	result := ColorM{}
 	add(&other, c, &result)
@@ -87,8 +86,7 @@ func (c *ColorM) Add(other ColorM) ColorM {
 // SetElement sets an element at (i, j).
 func (c *ColorM) SetElement(i, j int, element float64) {
 	if !c.initialized {
-		c.es = colorMatrixEsI()
-		c.initialized = true
+		*c = colorMI
 	}
 	c.es[i][j] = element
 }
diff --git a/geometrymatrix.go b/geometrymatrix.go
index c992f428a..3482c5eff 100644
--- a/geometrymatrix.go
+++ b/geometrymatrix.go
@@ -21,6 +21,14 @@ import (
 // GeoMDim is a dimension of a GeoM.
 const GeoMDim = 3
 
+var geoMI = GeoM{
+	initialized: true,
+	es: [2][3]float64{
+		{1, 0, 0},
+		{0, 1, 0},
+	},
+}
+
 // A GeoM represents a matrix to transform geometry when rendering an image.
 //
 // The initial value is identity.
@@ -29,13 +37,6 @@ type GeoM struct {
 	es          [GeoMDim - 1][GeoMDim]float64
 }
 
-func geometryMatrixEsI() [GeoMDim - 1][GeoMDim]float64 {
-	return [GeoMDim - 1][GeoMDim]float64{
-		{1, 0, 0},
-		{0, 1, 0},
-	}
-}
-
 func (g GeoM) dim() int {
 	return GeoMDim
 }
@@ -55,8 +56,7 @@ func (g GeoM) Element(i, j int) float64 {
 // This returns g.
 func (g *GeoM) Concat(other GeoM) GeoM {
 	if !g.initialized {
-		g.es = geometryMatrixEsI()
-		g.initialized = true
+		*g = geoMI
 	}
 	result := GeoM{}
 	mul(&other, g, &result)
@@ -68,8 +68,7 @@ func (g *GeoM) Concat(other GeoM) GeoM {
 // This returns g.
 func (g *GeoM) Add(other GeoM) GeoM {
 	if !g.initialized {
-		g.es = geometryMatrixEsI()
-		g.initialized = true
+		*g = geoMI
 	}
 	result := GeoM{}
 	add(&other, g, &result)
@@ -80,8 +79,7 @@ func (g *GeoM) Add(other GeoM) GeoM {
 // SetElement sets an element at (i, j).
 func (g *GeoM) SetElement(i, j int, element float64) {
 	if !g.initialized {
-		g.es = geometryMatrixEsI()
-		g.initialized = true
+		*g = geoMI
 	}
 	g.es[i][j] = element
 }