Gray scale rendering (Font smoothing)

The TrueType rasterizer supports gray scale rendering, an anti-aliasing technique that uses pixels in many shades of gray to represent character shapes, rather than the usual black-and-white. Gray scale rendering works in combination with the hints in a TrueType font to improve the appearance of curves, diagonals, and subtle design features. TrueType fonts can define the best combinations of hinting and gray scale to apply at different font sizes.