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

EN Designating and Selecting Fonts 23-17
When printing proportional fonts, the Character Plot (CP) command
uses the width of the Space control code to determine horizontal
spaces and the Line Feed height for determining vertical spacing.
The Extra Space (ES) command uses the horizontal escapement
distance (a font metric) to compute horizontal spaces and the Line
Feed height for determining vertical spacing. Both of the character
size commands (SI and SR) use cap height and average character
width in calculating character size. Otherwise, these commands
behave the same as they do with fixed-spaced fonts.
Designating and Selecting Fonts
If you intend to label with the default fixed-spaced font (Stick), you do
not need to use the SD or AD commands for designating standard
and alternate fonts. However, if you intend to use a different font (for
example, to match accompanying PCL text), you must use the SD or
AD commands to designate fonts before you can select those fonts
for labeling (using either SA or SS).
Standard and Alternate Fonts
The following outlines some of the principles to use when labeling
with different fonts:
z Designate the standard and alternate fonts using the SD and/or
AD commands before labeling. If you are using the Stick font
(the default) as your standard font, you need specify only your
alternate font.
z Select either the standard or alternate font, using either the SS or
SA command before labeling.
• Note that labeling always begins with the standard font, unless
you use the SA command before you begin your label (or finish
the previous label in the alternate font).
z Switch from the standard font to the alternate font, either using
SS and SA or the Shift In/Shift Out method. If you are changing
fonts within a text string, the Shift In/Shift Out method is usually
more efficient. Switch from the standard font to the alternate font
using the ASCII Shift Out control character (SO, decimal code
14). Switch from the alternate font to the standard font using the
ASCII Shift In control character (SI, decimal code 15). (Note that
a Shift In or Shift Out outside of the label command string is
ignored.)