Draw a motif on a grid, then repeat it around a circle -- or render just the motif on its own.
Split is how many times the pattern repeats around the circle.
Kept in this browser only -- give a drawing a name in the drawing dialog to add it here.
Click points on a grid to trace the motif, plus any separate shapes that repeat along with it -- it's turned into a pattern string for you.
Flatten scales how far the pattern's outer/inner lines sit from the original line, as two numbers "A B" (e.g. "2 3" for two-thirds the usual depth) -- leave blank for no change. Unit only matters for "Just the motif".
Optional. A named pattern is saved under Saved pattern, in this browser only -- leave it blank to just use the drawing.