Horizontal Bands
White boundary lines (only when Horizontal bands is on):
Grid
Same step on X and Y. Offsets shift where lines start (pixel phase).
Vertical splits
Equal-width columns: N segments → N − 1 lines. Offset moves every line by the same amount (pixels).
Skip bands: split lines use the same top / middle / bottom heights as Horizontal bands. Checked = do not draw through that band.
Box
Safe-area guide: equal inset on all sides from the shorter canvas dimension (%), then the inner rectangle is cropped to match the chosen band aspect ratio (centered).
Frame
Solid border on the canvas edges. Width is clamped so the inner area stays at least 1×1 px.