Serialization
Drawings are vector documents, not pictures. Draw on the left, then save, reload and export on the right. The compact format stores a handwriting point in a few bytes; the readable format is the same data as plain JSON for diffing and inspection.
Empty drawing canvas.
Save the drawing to see how it is stored.
The format carries a schema version. A document written by a newer version is refused with an explanation
rather than being partially read, and elements of unknown types are preserved untouched through a load and
save, so an old build never silently destroys work made by a new one.