1. A method comprising: receiving a glyph for display at a size on a raster output device; receiving a grid ratio, the grid ratio specifying an integer number of fine pixels of a high resolution grid that correspond to a device pixel of a raster of the output device; rendering, with one or more computers, the glyph at the size on the high resolution grid, the high resolution grid including fine pixels marked to represent the glyph and fine pixels that are unmarked; determining, with the one or more computers, for each line of pixels of the high resolution grid in a particular direction, a line-specific, per-transition adjustment number, the line-specific, per-transition adjustment number determined from a scaled stem width for the glyph; and in each line of pixels of the high resolution grid, marking or erasing the line-specific, per-transition adjustment number of fine pixels in the high resolution grid at each transition from a marked fine pixel to an unmarked fine pixel in the particular direction.