diff --git a/demos/kibodo/game/game.go b/demos/kibodo/game/game.go
index 360445a..4e1e3c5 100644
--- a/demos/kibodo/game/game.go
+++ b/demos/kibodo/game/game.go
@@ -2,7 +2,6 @@ package game
 
 import (
 	"fmt"
-	"image"
 
 	"github.com/hajimehoshi/ebiten/v2"
 	"github.com/hajimehoshi/ebiten/v2/ebitenutil"
@@ -73,6 +72,8 @@ func (g *game) showKeyboard() {
 		} else if input.Key == ebiten.KeyEnter {
 			g.userInput = nil
 			continue
+		} else if input.Key < 0 {
+			continue
 		}
 		g.userInput = append(g.userInput, []byte("<"+input.Key.String()+">")...)
 	}
@@ -89,10 +90,13 @@ func (g *game) Layout(outsideWidth, outsideHeight int) (int, int) {
 
 	g.w, g.h = outsideWidth, outsideHeight
 
-	g.buffer = ebiten.NewImageFromImage(image.NewRGBA(image.Rect(0, 0, g.w, g.h)))
+	g.buffer = ebiten.NewImage(g.w, g.h)
 
-	sizeH := 200
-	g.k.SetRect(0, sizeH, g.w, g.h-sizeH)
+	y := 200
+	if g.h > g.w && (g.h-g.w) > 200 {
+		y = g.h - g.w
+	}
+	g.k.SetRect(0, y, g.w, g.h-y)
 
 	return outsideWidth, outsideHeight
 }
diff --git a/go.mod b/go.mod
index 8ac7475..13d4455 100644
--- a/go.mod
+++ b/go.mod
@@ -3,15 +3,16 @@ module code.rocketnine.space/tslocum/kibodo
 go 1.17
 
 require (
-	github.com/hajimehoshi/ebiten/v2 v2.2.0-alpha.13.0.20210909171729-37771717cc52
+	github.com/hajimehoshi/ebiten/v2 v2.2.0-alpha.14.0.20210915040438-ec2f82342091
 	golang.org/x/image v0.0.0-20210628002857-a66eb6448b8d
 )
 
 require (
 	github.com/go-gl/glfw/v3.3/glfw v0.0.0-20210727001814-0db043d8d5be // indirect
-	golang.org/x/exp v0.0.0-20210910231120-3d0173ecaa1e // indirect
+	github.com/jezek/xgb v0.0.0-20210312150743-0e0f116e1240 // indirect
+	golang.org/x/exp v0.0.0-20210915225539-aeb18aa42a84 // indirect
 	golang.org/x/mobile v0.0.0-20210902104108-5d9a33257ab5 // indirect
 	golang.org/x/sync v0.0.0-20210220032951-036812b2e83c // indirect
-	golang.org/x/sys v0.0.0-20210910150752-751e447fb3d0 // indirect
+	golang.org/x/sys v0.0.0-20210915083310-ed5796bab164 // indirect
 	golang.org/x/text v0.3.7 // indirect
 )
diff --git a/go.sum b/go.sum
index ef399b3..132728d 100644
--- a/go.sum
+++ b/go.sum
@@ -98,12 +98,12 @@ github.com/grpc-ecosystem/go-grpc-prometheus v1.2.0/go.mod h1:8NvIoxWQoOIhqOTXgf
 github.com/grpc-ecosystem/grpc-gateway v1.9.5/go.mod h1:vNeuVxBJEsws4ogUvrchl83t/GYV9WGTSLVdBhOQFDY=
 github.com/hajimehoshi/bitmapfont/v2 v2.1.3 h1:JefUkL0M4nrdVwVq7MMZxSTh6mSxOylm+C4Anoucbb0=
 github.com/hajimehoshi/bitmapfont/v2 v2.1.3/go.mod h1:2BnYrkTQGThpr/CY6LorYtt/zEPNzvE/ND69CRTaHMs=
-github.com/hajimehoshi/ebiten/v2 v2.2.0-alpha.13.0.20210909171729-37771717cc52 h1:FVGJlUvpO/i9TiN/S1kpkPxIge7nR7R15Ux0zF3jr+4=
-github.com/hajimehoshi/ebiten/v2 v2.2.0-alpha.13.0.20210909171729-37771717cc52/go.mod h1:44O6eBPGyRv8YctRbfzaqUH2sek5UdXh0aLWOP02ELI=
+github.com/hajimehoshi/ebiten/v2 v2.2.0-alpha.14.0.20210915040438-ec2f82342091 h1:z3+aOqAqZhE0ppbhy89l5T3RDB7d+S9TiyGbtVJ3NvA=
+github.com/hajimehoshi/ebiten/v2 v2.2.0-alpha.14.0.20210915040438-ec2f82342091/go.mod h1:fS7PLZeV3mclX0J6qubENa9ms3NWmZdNJkCOeEHmF74=
 github.com/hajimehoshi/file2byteslice v0.0.0-20200812174855-0e5e8a80490e/go.mod h1:CqqAHp7Dk/AqQiwuhV1yT2334qbA/tFWQW0MD2dGqUE=
 github.com/hajimehoshi/go-mp3 v0.3.2/go.mod h1:qMJj/CSDxx6CGHiZeCgbiq2DSUkbK0UbtXShQcnfyMM=
 github.com/hajimehoshi/oto v0.6.1/go.mod h1:0QXGEkbuJRohbJaxr7ZQSxnju7hEhseiPx2hrh6raOI=
-github.com/hajimehoshi/oto/v2 v2.0.0-alpha.2/go.mod h1:rUKQmwMkqmRxe+IAof9+tuYA2ofm8cAWXFmSfzDN8vQ=
+github.com/hajimehoshi/oto/v2 v2.1.0-alpha.0.20210912073017-18657977e3dc/go.mod h1:rUKQmwMkqmRxe+IAof9+tuYA2ofm8cAWXFmSfzDN8vQ=
 github.com/hashicorp/consul/api v1.3.0/go.mod h1:MmDNSzIMUjNpY/mQ398R4bk2FnqQLoPndWW5VkKPlCE=
 github.com/hashicorp/consul/sdk v0.3.0/go.mod h1:VKf9jXwCTEY1QZP2MOLRhb5i/I/ssyNV1vwHyQBF0x8=
 github.com/hashicorp/errwrap v1.0.0/go.mod h1:YH+1FKiLXxHSkmPseP+kNlulaMuP3n2brvKWEqk/Jc4=
@@ -129,6 +129,8 @@ github.com/hudl/fargo v1.3.0/go.mod h1:y3CKSmjA+wD2gak7sUSXTAoopbhU08POFhmITJgmK
 github.com/inconshreveable/mousetrap v1.0.0/go.mod h1:PxqpIevigyE2G7u3NXJIT2ANytuPF1OarO4DADm73n8=
 github.com/influxdata/influxdb1-client v0.0.0-20191209144304-8bf82d3c094d/go.mod h1:qj24IKcXYK6Iy9ceXlo3Tc+vtHo9lIhSX5JddghvEPo=
 github.com/jakecoffman/cp v1.1.0/go.mod h1:JjY/Fp6d8E1CHnu74gWNnU0+b9VzEdUVPoJxg2PsTQg=
+github.com/jezek/xgb v0.0.0-20210312150743-0e0f116e1240 h1:dy+DS31tGEGCsZzB45HmJJNHjur8GDgtRNX9U7HnSX4=
+github.com/jezek/xgb v0.0.0-20210312150743-0e0f116e1240/go.mod h1:3P4UH/k22rXyHIJD2w4h2XMqPX4Of/eySEZq9L6wqc4=
 github.com/jfreymuth/oggvorbis v1.0.3/go.mod h1:1U4pqWmghcoVsCJJ4fRBKv9peUJMBHixthRlBeD6uII=
 github.com/jfreymuth/vorbis v1.0.2/go.mod h1:DoftRo4AznKnShRl1GxiTFCseHr4zR9BN3TWXyuzrqQ=
 github.com/jmespath/go-jmespath v0.0.0-20180206201540-c2b33e8439af/go.mod h1:Nht3zPeWKUH0NzdCt2Blrr5ys8VGpn0CEB0cQHVjt7k=
@@ -283,8 +285,8 @@ golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPh
 golang.org/x/exp v0.0.0-20190121172915-509febef88a4/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
 golang.org/x/exp v0.0.0-20190306152737-a1d7652674e8/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
 golang.org/x/exp v0.0.0-20190731235908-ec7cb31e5a56/go.mod h1:JhuoJpWY28nO4Vef9tZUw9qufEGTyX1+7lmHxV5q5G4=
-golang.org/x/exp v0.0.0-20210910231120-3d0173ecaa1e h1:W9ijN+u/MsYtKK8c9OVJM3Wc3GyrQO2hlRdbrwyzJMc=
-golang.org/x/exp v0.0.0-20210910231120-3d0173ecaa1e/go.mod h1:a3o/VtDNHN+dCVLEpzjjUHOzR+Ln3DHX056ZPzoZGGA=
+golang.org/x/exp v0.0.0-20210915225539-aeb18aa42a84 h1:rZZoVfcp9bNtyV7GbMqs6qTtgn/htRKdyfzKQ4EiLFE=
+golang.org/x/exp v0.0.0-20210915225539-aeb18aa42a84/go.mod h1:a3o/VtDNHN+dCVLEpzjjUHOzR+Ln3DHX056ZPzoZGGA=
 golang.org/x/image v0.0.0-20190227222117-0694c2d4d067/go.mod h1:kZ7UVZpmo3dzQBMxlp+ypCbDeSB+sBbTgSJuh5dn5js=
 golang.org/x/image v0.0.0-20190703141733-d6a02ce849c9/go.mod h1:FeLwcggjj3mMvU+oOTbSwawSJRM1uh48EjtB4UJZlP0=
 golang.org/x/image v0.0.0-20190802002840-cff245a6509b/go.mod h1:FeLwcggjj3mMvU+oOTbSwawSJRM1uh48EjtB4UJZlP0=
@@ -360,8 +362,8 @@ golang.org/x/sys v0.0.0-20210119212857-b64e53b001e4/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20210330210617-4fbd30eecc44/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210510120138-977fb7262007/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20210820121016-41cdb8703e55/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.0.0-20210910150752-751e447fb3d0 h1:xrCZDmdtoloIiooiA9q0OQb9r8HejIHYoHGhGCe1pGg=
-golang.org/x/sys v0.0.0-20210910150752-751e447fb3d0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.0.0-20210915083310-ed5796bab164 h1:7ZDGnxgHAMw7thfC5bEos0RDAccZKxioiWBhfIe+tvw=
+golang.org/x/sys v0.0.0-20210915083310-ed5796bab164/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.2/go.mod h1:bEr9sfX3Q8Zfm5fL9x+3itogRgK3+ptLWKqgva+5dAk=
diff --git a/key.go b/key.go
index 9b6cf65..b7d4968 100644
--- a/key.go
+++ b/key.go
@@ -4,6 +4,7 @@ import (
 	"github.com/hajimehoshi/ebiten/v2"
 )
 
+// Key represents a virtual key.
 type Key struct {
 	LowerLabel string
 	UpperLabel string
@@ -13,9 +14,11 @@ type Key struct {
 	x, y int
 	w, h int
 
-	pressed bool
+	pressed        bool
+	pressedTouchID ebiten.TouchID
 }
 
+// Input represents the input from a key press.
 type Input struct {
 	Rune rune
 	Key  ebiten.Key
diff --git a/keyboard.go b/keyboard.go
index 454a0c4..ad23d3c 100644
--- a/keyboard.go
+++ b/keyboard.go
@@ -29,7 +29,8 @@ type Keyboard struct {
 
 	keys [][]*Key
 
-	background      *ebiten.Image
+	backgroundLower *ebiten.Image
+	backgroundUpper *ebiten.Image
 	backgroundDirty bool
 
 	op *ebiten.DrawImageOptions
@@ -46,7 +47,7 @@ type Keyboard struct {
 	labelFont font.Face
 }
 
-// NewKeyboard returns a new Keyboard.
+// NewKeyboard returns a new Keyboard widget.
 func NewKeyboard() *Keyboard {
 	fontFace, err := defaultFontFace(64)
 	if err != nil {
@@ -58,7 +59,9 @@ func NewKeyboard() *Keyboard {
 		op: &ebiten.DrawImageOptions{
 			Filter: ebiten.FilterNearest,
 		},
-		background:      ebiten.NewImage(1, 1),
+		keys:            KeysQWERTY,
+		backgroundLower: ebiten.NewImage(1, 1),
+		backgroundUpper: ebiten.NewImage(1, 1),
 		backgroundColor: color.Black,
 		labelFont:       fontFace,
 	}
@@ -93,10 +96,12 @@ func (k *Keyboard) SetRect(x, y, w, h int) {
 	k.backgroundDirty = true
 }
 
+// GetKeys returns the keys of the keyboard.
 func (k *Keyboard) GetKeys() [][]*Key {
 	return k.keys
 }
 
+// SetKeys sets the keys of the keyboard.
 func (k *Keyboard) SetKeys(keys [][]*Key) {
 	k.keys = keys
 
@@ -104,12 +109,15 @@ func (k *Keyboard) SetKeys(keys [][]*Key) {
 	k.backgroundDirty = true
 }
 
+// SetLabelFont sets the key label font.
 func (k *Keyboard) SetLabelFont(face font.Face) {
 	k.labelFont = face
 
 	k.backgroundDirty = true
 }
 
+// SetHideShortcuts sets the key shortcuts which, when pressed, will hide the
+// keyboard.
 func (k *Keyboard) SetHideShortcuts(shortcuts []ebiten.Key) {
 	k.hideShortcuts = shortcuts
 }
@@ -126,8 +134,9 @@ func (k *Keyboard) updateKeyRects() {
 		}
 	}
 
-	cellPaddingW := 7
-	cellPaddingH := 7
+	// TODO user configurable
+	cellPaddingW := 2
+	cellPaddingH := 2
 
 	cellH := (k.h - (cellPaddingH * (len(k.keys) - 1))) / len(k.keys)
 
@@ -186,6 +195,7 @@ func (k *Keyboard) handleHideKey(inputKey ebiten.Key) bool {
 	return false
 }
 
+// Hit handles a key press.
 func (k *Keyboard) Hit(key *Key) {
 	input := key.LowerInput
 	if k.shift {
@@ -194,7 +204,7 @@ func (k *Keyboard) Hit(key *Key) {
 
 	if input.Key == ebiten.KeyShift {
 		k.shift = !k.shift
-		k.backgroundDirty = true
+		ebiten.ScheduleFrame()
 		return
 	} else if k.handleHideKey(input.Key) {
 		// Hidden
@@ -204,7 +214,7 @@ func (k *Keyboard) Hit(key *Key) {
 	k.inputBuffer <- input
 }
 
-// Update handles user input.
+// Update handles user input. This function is called by Ebiten.
 func (k *Keyboard) Update() error {
 	if !k.visible {
 		return nil
@@ -232,6 +242,7 @@ func (k *Keyboard) Update() error {
 		}
 	}
 	// Handle mouse input
+	pressDuration := 50 * time.Millisecond
 	if inpututil.IsMouseButtonJustReleased(ebiten.MouseButtonLeft) {
 		x, y := ebiten.CursorPosition()
 
@@ -248,7 +259,7 @@ func (k *Keyboard) Update() error {
 
 			// TODO replace with pressUntil
 			go func() {
-				time.Sleep(50 * time.Millisecond)
+				time.Sleep(pressDuration)
 
 				key.pressed = false
 				ebiten.ScheduleFrame()
@@ -260,6 +271,15 @@ func (k *Keyboard) Update() error {
 		key := k.at(x, y)
 		if key != nil {
 			key.pressed = true
+
+			for _, rowKeys := range k.keys {
+				for _, rowKey := range rowKeys {
+					if rowKey == key || !rowKey.pressed {
+						continue
+					}
+					rowKey.pressed = false
+				}
+			}
 		}
 	}
 	// Handle touch input
@@ -268,17 +288,47 @@ func (k *Keyboard) Update() error {
 		x, y := ebiten.TouchPosition(id)
 
 		key := k.at(x, y)
-		if key != nil {
+		if key != nil && !key.pressed {
 			key.pressed = true
+			key.pressedTouchID = id
+
+			for _, rowKeys := range k.keys {
+				for _, rowKey := range rowKeys {
+					if rowKey != key && rowKey.pressed {
+						rowKey.pressed = false
+					}
+				}
+			}
 
 			k.Hit(key)
 
-			// TODO replace with pressUntil
 			go func() {
-				time.Sleep(50 * time.Millisecond)
+				var touchIDs []ebiten.TouchID
+				t := time.NewTicker(pressDuration)
+				for range t.C {
+					touchIDs = ebiten.AppendTouchIDs(touchIDs[:0])
+
+					var found bool
+					for _, touchID := range touchIDs {
+						if id == touchID {
+							found = true
+							break
+						}
+					}
 
-				key.pressed = false
-				ebiten.ScheduleFrame()
+					if found {
+						tx, ty := ebiten.TouchPosition(id)
+						if tx != 0 || ty != 0 {
+							x, y = tx, ty
+						}
+					}
+
+					if !found {
+						key.pressed = false
+						ebiten.ScheduleFrame()
+						return
+					}
+				}
 			}()
 		}
 	}
@@ -294,44 +344,63 @@ func (k *Keyboard) drawBackground() {
 		return
 	}
 
-	if k.background == nil || k.background.Bounds() != image.Rect(0, 0, k.w, k.h) || k.backgroundColor != k.lastBackgroundColor {
-		k.background = ebiten.NewImageFromImage(image.NewRGBA(image.Rect(0, 0, k.w, k.h)))
-		k.background.Fill(k.backgroundColor)
+	if k.backgroundLower.Bounds() != image.Rect(0, 0, k.w, k.h) || k.backgroundUpper.Bounds() != image.Rect(0, 0, k.w, k.h) || k.backgroundColor != k.lastBackgroundColor {
+		k.backgroundLower = ebiten.NewImage(k.w, k.h)
+		k.backgroundLower.Fill(k.backgroundColor)
+
+		k.backgroundUpper = ebiten.NewImage(k.w, k.h)
+		k.backgroundUpper.Fill(k.backgroundColor)
 
 		k.lastBackgroundColor = k.backgroundColor
 	}
 
-	for _, rowKeys := range k.keys {
-		for _, key := range rowKeys {
-			label := key.LowerLabel
-			if k.shift {
-				label = key.UpperLabel
-			}
+	var img *ebiten.Image
+	for i := 0; i < 2; i++ {
+		shift := i == 1
+		for _, rowKeys := range k.keys {
+			for _, key := range rowKeys {
+				if img == nil {
+					img = ebiten.NewImage(key.w, key.h)
+				} else {
+					bounds := img.Bounds()
+					if bounds.Dx() != key.w || bounds.Dy() != key.h {
+						img = ebiten.NewImage(key.w, key.h)
+					}
+				}
 
-			// Draw key background
-			img := ebiten.NewImageFromImage(image.NewRGBA(image.Rect(0, 0, key.w, key.h)))
-			img.Fill(color.RGBA{100, 100, 100, 255})
+				label := key.LowerLabel
+				if shift {
+					label = key.UpperLabel
+				}
 
-			// Draw key label
-			bounds := text.BoundString(k.labelFont, label)
-			x := (key.w - bounds.Dx()) / 2
-			if x < 0 {
-				x = 0
-			}
-			y := key.h / 2
-			text.Draw(img, label, k.labelFont, x, y, color.White)
+				// Draw key background
+				img.Fill(color.RGBA{100, 100, 100, 255})
 
-			// Draw key
-			k.op.GeoM.Reset()
-			k.op.GeoM.Translate(float64(key.x), float64(key.y))
-			k.background.DrawImage(img, k.op)
+				// Draw key label
+				bounds := text.BoundString(k.labelFont, label)
+				x := (key.w - bounds.Dx()) / 2
+				if x < 0 {
+					x = 0
+				}
+				y := key.h / 2
+				text.Draw(img, label, k.labelFont, x, y, color.White)
 
-			k.op.ColorM.Reset()
+				// Draw key
+				k.op.GeoM.Reset()
+				k.op.GeoM.Translate(float64(key.x), float64(key.y))
+
+				if !shift {
+					k.backgroundLower.DrawImage(img, k.op)
+				} else {
+					k.backgroundUpper.DrawImage(img, k.op)
+				}
+				k.op.ColorM.Reset()
+			}
 		}
 	}
 }
 
-// Draw draws the widget on the provided image.
+// Draw draws the widget on the provided image.  This function is called by Ebiten.
 func (k *Keyboard) Draw(target *ebiten.Image) {
 	if !k.visible {
 		return
@@ -342,10 +411,17 @@ func (k *Keyboard) Draw(target *ebiten.Image) {
 		k.backgroundDirty = false
 	}
 
+	var background *ebiten.Image
+	if !k.shift {
+		background = k.backgroundLower
+	} else {
+		background = k.backgroundUpper
+	}
+
 	k.op.GeoM.Reset()
 	k.op.GeoM.Translate(float64(k.x), float64(k.y))
 	k.op.ColorM.Scale(1, 1, 1, k.alpha)
-	target.DrawImage(k.background, k.op)
+	target.DrawImage(background, k.op)
 	k.op.ColorM.Reset()
 
 	// Draw pressed keys
@@ -360,7 +436,7 @@ func (k *Keyboard) Draw(target *ebiten.Image) {
 			k.op.GeoM.Translate(float64(k.x+key.x), float64(k.y+key.y))
 			k.op.ColorM.Scale(0.75, 0.75, 0.75, k.alpha)
 
-			target.DrawImage(k.background.SubImage(image.Rect(key.x, key.y, key.x+key.w, key.y+key.h)).(*ebiten.Image), k.op)
+			target.DrawImage(background.SubImage(image.Rect(key.x, key.y, key.x+key.w, key.y+key.h)).(*ebiten.Image), k.op)
 			k.op.ColorM.Reset()
 		}
 	}
@@ -394,6 +470,7 @@ func (k *Keyboard) Show(inputBuffer chan *Input) {
 	k.visible = true
 }
 
+// Visible returns whether the keyboard is currently shown.
 func (k *Keyboard) Visible() bool {
 	return k.visible
 }
diff --git a/keyboard_test.go b/keyboard_test.go
index 824d29a..39177ce 100644
--- a/keyboard_test.go
+++ b/keyboard_test.go
@@ -1,15 +1,24 @@
 package kibodo
 
 import (
+	"runtime"
 	"testing"
+	"time"
+
+	"github.com/hajimehoshi/ebiten/v2"
 )
 
-func BenchmarkKeyboard_Draw(b *testing.B) {
-	ch := make(chan *Input, 10)
+// TODO test presses registered
 
-	k := NewKeyboard()
-	k.SetRect(0, 0, 100, 100)
-	k.Show(ch)
+func TestKeyboard_Draw(t *testing.T) {
+	k, _ := newTestKeyboard()
+
+	// Warm caches
+	k.drawBackground()
+}
+
+func BenchmarkKeyboard_Draw(b *testing.B) {
+	k, _ := newTestKeyboard()
 
 	// Warm caches
 	k.drawBackground()
@@ -20,3 +29,60 @@ func BenchmarkKeyboard_Draw(b *testing.B) {
 		k.drawBackground()
 	}
 }
+
+func BenchmarkKeyboard_Press(b *testing.B) {
+	go func() {
+		time.Sleep(2 * time.Second)
+
+		k, _ := newTestKeyboard()
+
+		// Warm caches
+		k.drawBackground()
+
+		b.ReportAllocs()
+		b.ResetTimer()
+		for i := 0; i < b.N; i++ {
+			k.drawBackground()
+			k.keys[0][0].pressed = true
+			k.drawBackground()
+			k.keys[0][0].pressed = false
+		}
+	}()
+
+	runtime.LockOSThread()
+
+	err := ebiten.RunGame(NewDummyGame())
+	if err != nil {
+		b.Error(err)
+	}
+}
+
+func newTestKeyboard() (*Keyboard, chan *Input) {
+	ch := make(chan *Input, 10)
+
+	k := NewKeyboard()
+	k.SetRect(0, 0, 300, 100)
+	k.Show(ch)
+
+	return k, ch
+}
+
+type DummyGame struct {
+	ready bool
+}
+
+func (d *DummyGame) Update() error {
+	return nil
+}
+
+func (d *DummyGame) Draw(screen *ebiten.Image) {
+	d.ready = true
+}
+
+func (d *DummyGame) Layout(outsideWidth, outsideHeight int) (screenWidth, screenHeight int) {
+	return outsideWidth, outsideHeight
+}
+
+func NewDummyGame() *DummyGame {
+	return &DummyGame{}
+}
diff --git a/keys.go b/keys.go
index e24ab19..e9d3760 100644
--- a/keys.go
+++ b/keys.go
@@ -2,6 +2,7 @@ package kibodo
 
 import "github.com/hajimehoshi/ebiten/v2"
 
+// KeysQWERTY is a standard QWERTY keyboard layout.
 var KeysQWERTY = [][]*Key{
 	{
 		{