A method of rendering a stroked curve for display in a graphics processing system in which an input stroked curve 2 to be displayed, such as a character in a computer font or a portion thereof, is defined in user space 4 and projected into a surface space 6 for display. For each of one or more sampling points in the surface space 6, a corresponding sampling position in a projected space 12 is determined, and predetermined information is used to estimate the extent in a defined direction of a projected form of the stroked curve in the projected space 12 at a position along the length of the projected form of the stroked curve corresponding to the position along the length of the projected form of the stroked curve of the sampling position in the projected space 12. The estimated extent is then used to determine whether the sampling position in question falls within the stroked curve or not, thereby allowing suitable rendering data to be assigned to the sampling point.