XFT: Forbid XFT rendering on bitmaps (depth-1 pixmaps) In theory it could work if XFT would just turn gray into either black or white. But XFT doesn't do it and simply draw nothing without failing in any way. To prevent this silent failures, forbid drawing XFT onto bitmaps (depth-1 pixmaps). After all, the while point of XFT is to use anti-aliased fonts.