Instead of the solid colour strokes in 017 and 018, this turns them into spines where the rounded spokes fill out the width of the stroke.
I selected a design for the puzzle which had a very distinct gradient running across it, making it much easier to put together from one side rather than doing all the edge pieces first.
Each jigsaw is designed and developed entirely in the browser. Above are some random outputs generated on the fly just for you – crack open the explorer for finer control of the parameters.