Chipboard is a great material used to make simple wind turbine blades. It is stiff, easy to cut, lightweight, low cost and recyclable. Each package comes with 50 chipboard sheets that are 3 in by 12 in. Each sheet is approximately 1.5 mm thick, so they will stay stiff in a light wind but bend in a strong one. Chipboard has replaced coroplast blade material. Coroplast is no longer sold by KidWind or Vernier since it is not able to be recycled in many communities.