DISK creates files to store rendered versions of Bitstream fonts if the files do not already exist, reads previously rendered characters from the font files, and appends rendered versions of new characters to the font files as they are encountered. This method is slower on some hosts, but it may work in memory-constrained conditions where the other rendering methods fail. Font files are not used even if they already exist. This is the default and should be the fastest method on hosts that support virtual memory.
NONE disables the font rendering features.
READ reads existing rendered font files but does not create new font files or write new characters to existing font files. This is useful only when font files already exist in the rendered font library. All rights reserved.