A method for determining an actual state of a support bar for supporting a plate-type workpiece, in particular a metal sheet, on a machine tool for cutting workpieces using a cutting beam, wherein in a desired state of the support bar • the support bar is provided with a plurality of supporting projections which are adjacent to one another in a longitudinal direction of the support bar, a projection gap being formed between mutually adjacent supporting projections, • the supporting projections protrude from a main body of the support bar toward a supporting side of the support bar in the direction of a height of the support bar transversely with respect to the longitudinal direction of the support bar, wherein the supporting side of the support bar is designed for supporting the workpiece, and • the supporting projections have a defined desired geometry, viewed from a longitudinal side of the support bar running in the longitudinal direction of the support bar, the geometry having a projection height by which the supporting projections extend along a defined support bar height range associated with the supporting projections, characterized in that an actual geometry of the supporting projections on the support bar is determined according to a light section method by • projecting a line of light extending in the longitudinal direction of the support bar from a light source onto the longitudinal side of the support bar and using the line of light to scan the longitudinal side of the support bar over at least part of the support bar height range associated with the supporting projections in the direction of the height of the support bar, • detecting the longitudinal side of the support bar scanned by the line of light within the extent of the scan using an optical detector, thereby generating an image of the longitudinal side of the support bar, and • determining the actual geometry of the supporting projections based on the generated image of the longitudinal side of the support bar using an evaluation device and the determined actual geometry of the supporting projections is compared with the defined desired geometry of the supporting projections using a comparison device. • the support bar is provided with a plurality of supporting projections which are adjacent to one another in a longitudinal direction of the support bar, a projection gap being formed between mutually adjacent supporting projections, • the supporting projections protrude from a main body of the support bar toward a supporting side of the support bar in the direction of a height of the support bar transversely with respect to the longitudinal direction of the support bar, wherein the supporting side of the support bar is designed for supporting the workpiece, and • the supporting projections have a defined desired geometry, viewed from a longitudinal side of the support bar running in the longitudinal direction of the support bar, the geometry having a projection height by which the supporting projections extend along a defined support bar height range associated with the supporting projections, an actual geometry of the supporting projections on the support bar is determined according to a light section method by • projecting a line of light extending in the longitudinal direction of the support bar from a light source onto the longitudinal side of the support bar and using the line of light to scan the longitudinal side of the support bar over at least part of the support bar height range associated with the supporting projections in the direction of the height of the support bar, • detecting the longitudinal side of the support bar scanned by the line of light within the extent of the scan using an optical detector, thereby generating an image of the longitudinal side of the support bar, and • determining the actual geometry of the supporting projections based on the generated image of the longitudinal side of the support bar using an evaluation device and • projecting a line of light extending in the longitudinal direction of the support bar from a light source onto the longitudinal side of the support bar and using the line of light to scan the longitudinal side of the support bar over at least part of the support bar height range associated with the supporting projections in the direction of the height of the support bar, • detecting the longitudinal side of the support bar scanned by the line of light within the extent of the scan using an optical detector, thereby generating an image of the longitudinal side of the support bar, and • determining the actual geometry of the supporting projections based on the generated image of the longitudinal side of the support bar using an evaluation device the determined actual geometry of the supporting projections is compared with the defined desired geometry of the supporting projections using a comparison device.