HP PCL/PJL reference (PCL 5 Printer Language) - Technical Reference Manual Part II

24-6 Programming Hints EN
To ensure compatibility with future products, select fonts by specifying
all of the font characteristics. If all of the characteristics are not
designated, the primary and secondary font tables in the printer may
not contain the correct information to select the requested font from
those available in the printer.
The shortcut method of font selection is not recommended (as
documented in some previous font product literature) and may not
result in the desired font change. This is due to the increased number
of available fonts in the printer.
The transparent print data command is required to access printable
characters with character codes in the decimal range of 0, 7-15, and
27 in the PC symbol sets.
All information about the design of a font, as well as the design of its
characters, can be found in the font and character descriptors.
A Space control code is executed when an attempt is made to print a
non-existent character.
Using an ID number which has not been associated with a font results
in no font change.
Font designers should not define the space character. Use the
printer’s Space control code should be used for character spacing.
Defining the space character in the font results in a significant
reduction in performance and inhibits the HMI command with
proportional fonts.
Note Refer to “HP-GL/2 Vector Graphics” later in the chapter for hints on
using HP-GL/2 text.