The optimum bending angle for a J-tip is dependent upon the desired application, since the geometry of the J-tip involves an inherent trade-off between performance on horizontal surfaces and vertical sidewalls. A bending angle of 90 deg might be optimum for imaging vertical sidewalls, since the tip would be normal to the surface. However, this would increase the geometrical clearance requirements of the tip in narrow trenches, and it would result in a blunt tip–sample contact region on horizontal surfaces, along with a corresponding impact on resolution.