Sketch canvas

The Sketch canvas holds freehand drawing as vector strokes rather than as a bitmap. A stroke is a recorded path, so it can be undone, erased or manipulated individually after the fact, and it scales without becoming pixellated.

Input

Sketch is built for pen and touch as well as for a mouse. Where a stylus is available, drawing uses it directly, with palm rejection so resting your hand on the surface does not draw a stray line.

Mouse drawing works too — a point worth stating because it was once broken. The canvas was invisible to mouse input for a while because a hard-coded list of recognised canvas kinds had not been updated when Sketch was added. It is fixed, and the list that caused it is no longer hard-coded.

Editing

• Enter on a selected Sketch canvas begins drawing.
• Undo removes the last stroke, not the last few pixels.
• Erase removes whole strokes.
• Escape leaves the canvas.

Storage

Strokes are stored as geometry in the notebook database, not as an image file. That keeps a sketch small, keeps it editable indefinitely, and means it can be re-rendered at any size.