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

17-20 An Introduction to HP-GL/2 Vector Graphics EN
HP-GL/2 Units of Measure
In HP-GL/2 mode, you can measure along the X,Y axes and express
coordinates using two types of units: plotter units and user-units.
Plotter Units
One plotter unit equals 0.025 mm. When specifying distances in
plotter units, the printer converts the number of plotter units to
equivalent dot coordinates before printing. Under default conditions,
the printer uses plotter units.
The following table lists equivalent measurements for plotter units.
User-units
The size of units along the X and Y axes may be redefined using
the Scale (SC) command. User-units allow you to customize the
coordinate system to represent any value. For example, you could
plot the moon cycle for the year by dividing the X-axis into 31 units for
days of the month and the Y-axis into 12 units for months of the year.
To mark a point on December 25, you would give the coordinate
(25,12) rather than calculating the exact location in plotter units.
Before printing, the printer internally converts user-units to dot
locations.
Table 17-7
PlotterUnits EquivalentValue
1 plu = 0.025 mm (≈ 0.00098 in.)
40 plu = 1 mm
1016 plu = 1 in.
3.39 plu = 1 dot @ 300 dpi