When sourcing a plastic kayak mould, the primary focus should be on the mould material and surface treatment. Most high-quality kayak moulds are made from A356 or 6061 aluminum alloy via CNC machining or casting, as aluminum offers excellent thermal conductivity for the rotational molding (rotomolding) process. Ensure the mould has a wall thickness uniformity of ±1mm to prevent hot spots. Additionally, the surface finish (e.g., sandblasted, Teflon-coated, or mirror-polished) is critical as it determines the final texture of the kayak and the ease of demoulding.