A gas-levitated substrate backing system includes a gas-levitating backer structure which is used for providing a non-contact force onto a surface of a substrate. The gas-levitating backer structure has an output face including three or more output openings. A gas source provides a gas flow through the output openings to levitate the gas-levitating backer structure over the surface of the substrate. The gas-levitating backer structure is freely moveable in a direction normal to the surface of the substrate.