The cutting component of a card scraper is the burred edge of the scraper. The burr is a sharp hook of metal which is turned on the edge of the scraper by burnishing with a burnisher or steel rod. A file or sharpening stone is used to joint the edge of the scraper before burnishing. Cabinet makers typically joint the edge square, or at a right angle to the face of the scraper, which allows a fine burr to be turned on both sides. Luthiers often use a beveled edge, which allows a more aggressive burr, but on one side only.