Seedream 5.0 Pro Layerize returns one finished image as editable parts: a base layer plus up to 16 transparent PNG elements, with the background rebuilt behind everything it lifts. The prompt is optional: leave it empty for a full automatic split, name the parts you want, or address a region with x1 y1 x2 y2 on a 0 to 1000 grid so everything outside stays in the base. Set size to 1K, 1.5K or 2K rather than auto, which takes its tier from the source. Cost is flat per run, not per layer, so dense compositions separate cheaply. Layers arrive cropped to their own bounds, not aligned to the source canvas.