Methods disclosed permit the identification of frame buffer pixels for trapping. In some embodiments, flags associated with pixels in the frame buffer may be used to provide an indication of pixels for trapping. A bit in a flag associated with a pixel may be set when the pixel is painted, if the luminosity value of the pixel does not exceed a luminosity threshold. In some embodiments, the method discloses a process for updating the value of the bit through the rasterization process. The pixel may be identified as a candidate for trapping based on the value of the at least one bit at trapping time.