diff --git a/src/element.toit b/src/element.toit
index b68d965..55652df 100644
--- a/src/element.toit
+++ b/src/element.toit
@@ -7,7 +7,7 @@ import bitmap show *
 import .four-gray as four-gray
 import .true-color as true-color
 import .gray-scale as gray-scale
-import .one-byte as one-byte
+import .one-byte_ as one-byte
 import .style show *
 import .pixel-display
 import font show Font
diff --git a/src/four-gray.toit b/src/four-gray.toit
index 549b073..6c11bfc 100644
--- a/src/four-gray.toit
+++ b/src/four-gray.toit
@@ -3,7 +3,7 @@
 // found in the LICENSE file.
 
 /**
-Constants useful for $PixelDisplay.four-gray.
+Constants useful for $pixel-display.PixelDisplay.four-gray.
 For use with e-paper displays with four tones of gray.
 */
 
@@ -11,8 +11,8 @@ import bitmap show *
 import font show Font
 
 import .pixel-display
-import .two-bit-texture
-import .two-bit-texture as two-bit
+import .pixel-display as pixel-display
+import .two-bit_ as two-bit
 
 /// Color value for use with $PixelDisplay.four-gray.
 WHITE ::= 0
diff --git a/src/gray-scale.toit b/src/gray-scale.toit
index e8557ab..5d952cf 100644
--- a/src/gray-scale.toit
+++ b/src/gray-scale.toit
@@ -3,13 +3,17 @@
 // found in the LICENSE file.
 
 /**
-Constants useful for $PixelDisplay.gray-scale.
+Constants useful for $pixel-display.PixelDisplay.gray-scale.
+These are displays with 8-bit pixels, where each pixel is a gray-scale value
+  from 0 (black) to 255 (white).
 */
 
 import bitmap show *
 import font show Font
+
 import .pixel-display
-import .one-byte
+import .pixel-display as pixel-display
+import .one-byte_
 
 /// Color value for use with $PixelDisplay.gray-scale.
 WHITE ::= 255
diff --git a/src/one-byte.toit b/src/one-byte_.toit
similarity index 100%
rename from src/one-byte.toit
rename to src/one-byte_.toit
diff --git a/src/pixel-display.toit b/src/pixel-display.toit
index e00abb1..4e03e8e 100644
--- a/src/pixel-display.toit
+++ b/src/pixel-display.toit
@@ -15,12 +15,12 @@ import .bar-code
 import .element
 import .two-color as two-color
 import .three-color as three-color
-import .two-bit-texture as two-bit
+import .two-bit_ as two-bit
 import .four-gray as four-gray
 import .true-color as true-color
 import .gray-scale as gray-scale
 import .several-color as several-color
-import .one-byte as one-byte
+import .one-byte_ as one-byte
 import .style
 
 FLAG-2-COLOR ::=         0b1
@@ -749,9 +749,24 @@ abstract class Canvas:
   */
   abstract create-similar -> Canvas
 
+  /**
+  Sets all pixels in the canvas to the given color.
+  For true-color canvases, the color has the form 0xRRGGBB.
+  For gray-scale canvases, the color has the form 0xGG.
+  For other canvases types, constants are defined in their respective import
+    files.
+  */
   abstract set-all-pixels color/int -> none
 
+  /**
+  Returns true for true-color and gray-scale canvases that support
+    8-bit drawing methods.
+  */
   abstract supports-8-bit -> bool
+
+  /**
+  Returns true for gray-scale canvases and two-color black/white canvases.
+  */
   abstract gray-scale -> bool
 
   /**
@@ -924,8 +939,7 @@ abstract class Canvas:
     descenders or starts with a character like "J" or "/", which in many fonts
     extend to the left of their origin.
   */
-  abstract text x/int y/int --text/string --color/int --font/Font --orientation/int
-  abstract text x/int y/int --text/string --color/int --font/Font
+  abstract text x/int y/int --text/string --color/int --font/Font --orientation/int=0
 
   /**
   Draws the given bitmap on the canvas.
diff --git a/src/several-color.toit b/src/several-color.toit
index 66bbec5..67e1365 100644
--- a/src/several-color.toit
+++ b/src/several-color.toit
@@ -4,7 +4,7 @@
 
 import bitmap show *
 import font show Font
-import .one-byte
+import .one-byte_
 import .two-color as two-color
 import .pixel-display
 
diff --git a/src/style.toit b/src/style.toit
index 76c0626..2591335 100644
--- a/src/style.toit
+++ b/src/style.toit
@@ -7,7 +7,7 @@ import bitmap show ORIENTATION-0 ORIENTATION-90 ORIENTATION-180 ORIENTATION-270
 import font show Font
 
 import .element as element
-import .one-byte as one-byte
+import .one-byte_ as one-byte
 import .pixel-display
 
 ALIGN-LEFT ::= 0
diff --git a/src/three-color.toit b/src/three-color.toit
index d267e25..f1e593b 100644
--- a/src/three-color.toit
+++ b/src/three-color.toit
@@ -3,15 +3,15 @@
 // found in the LICENSE file.
 
 /**
-Constants useful for $PixelDisplay.three-color.
+Constants useful for $pixel-display.PixelDisplay.three-color.
 For use with e-paper black, white, and red displays.
 */
 
 import font show Font
 
 import .pixel-display
-import .two-bit-texture
-import .two-bit-texture as two-bit
+import .pixel-display as pixel-display
+import .two-bit_ as two-bit
 
 WHITE ::= 0
 BLACK ::= 1
diff --git a/src/true-color.toit b/src/true-color.toit
index 429f0bc..543a86c 100644
--- a/src/true-color.toit
+++ b/src/true-color.toit
@@ -3,14 +3,18 @@
 // found in the LICENSE file.
 
 /**
-Functions and constants useful for the RGB $PixelDisplay.true-color display.
+Functions and constants useful for the RGB
+  $pixel-display.PixelDisplay.true-color display.
+See for example https://pkg.toit.io/package/github.com%2Ftoitware%2Ftoit-color-tft
 */
 
 import binary show BIG-ENDIAN
 import bitmap show *
 import font show Font
+
 import .gray-scale as gray-scale_
 import .pixel-display
+import .pixel-display as pixel-display
 
 /**
 Create a 24 bit color from three components in the 0-255 range.
diff --git a/src/two-bit-texture.toit b/src/two-bit_.toit
similarity index 100%
rename from src/two-bit-texture.toit
rename to src/two-bit_.toit
diff --git a/src/two-color.toit b/src/two-color.toit
index dbd87db..67894d1 100644
--- a/src/two-color.toit
+++ b/src/two-color.toit
@@ -3,7 +3,7 @@
 // found in the LICENSE file.
 
 /**
-Constants useful for black-and-white $PixelDisplay.two-color.
+Constants useful for black-and-white $pixel-display.PixelDisplay.two-color.
 For use with e-paper displays and the SSD1306 128x64 display
   (driver at https://pkg.toit.io/package/ssd1306&url=github.com%2Ftoitware%2Ftoit-ssd1306&index=latest)
 */
@@ -12,10 +12,10 @@ import bitmap show *
 import font show Font
 
 import .pixel-display
+import .pixel-display as pixel-display
 
 WHITE ::= 0
 BLACK ::= 1
-TRANSPARENT ::= 3
 
 // The canvas contains a bitmapped ByteArray.
 // Starts off with/ all pixels white.
diff --git a/tests/texture-test-slow.toit b/tests/texture-test-slow.toit
index b024e09..30251c0 100644
--- a/tests/texture-test-slow.toit
+++ b/tests/texture-test-slow.toit
@@ -1,4 +1,4 @@
-// Copyright (C) 2020 Toitware ApS.
+// Copyright (C) 2023 Toitware ApS.
 // Use of this source code is governed by a Zero-Clause BSD license that can
 // be found in the TESTS_LICENSE file.
 
@@ -10,7 +10,7 @@ import font show *
 
 import pixel-display show Transform
 import pixel-display.four-gray
-import pixel-display.two-bit-texture as two-bit
+import pixel-display.two-bit_ as two-bit
 import pixel-display.three-color
 import pixel-display.true-color
 import pixel-display.two-color