Patutiki means "strike an image", and the striking is literal: candlenut kernels burned on stone, the soot scraped off and dried on banana leaves, bound with coconut oil, driven in with bone combs cut to different widths for different line weights.
The ground is a body. Zones follow anatomy rather than a rectangle, each one filled with its own motif and butted hard against its neighbour, until on high-status men the field reads near-black. The whole grammar is solid mass against hairline, with almost nothing in between.