Transparent Print Data Command; Example - HP PCL 5 Reference Manual

Transparent Print Data Command

The Transparent Print Data command provides printing access to
those characters which the printer normally defines as unprintable.
These characters include decimal character codes 0, 7-15, and 27.
Default = N/A
Range =
Each transparent print data byte is interpreted as a single character
code. The appropriate character is printed if one exists; otherwise, a
Space is processed. For example, control codes such as LF, CR, FF
are treated as print data while in Transparent Print Data mode.

Example

Assuming the currently selected symbol set is PC-8, send the
following to print musical notes (decimal code 14):
The brackets "[ ]" are provided for clarity and are not part of the
command sequence.
Note In the ASCII symbol set, decimal 14 is the Shift Out control code (no
printable character exists), however, in the PC-8 symbol set, decimal
code 14 is also the musical notes character (printable from
transparency mode). Refer to Appendix A for character codes for the
various symbol sets.
8-28 PCL Font Selection
E
[Transparent Print Data]
& p # X
C
# =Number of bytes of transparent print data.
0 - 32767
E
&p1X
[ASCII 14]
C
EN