We had a great time weight testing the stools at the University of Windsor in Ontario. These cutting edge facilities allowed us to test the stools for weights in excess of 3000lbs. The organic nature of the compound curves combined with the elasticity of the polyethylene proved to be incredibly robust. Even under such extreme force, the stools would only gradually deform in shape, never tearing or bursting in any way that would create an an unsafe circumstance for the user.