HP 4 FAMILY - Manual (Page 84)

Stroke Weight (UINT16)—This field specifies the stroke
weights which the printer is allowed to provide using the
pseudo-bold enhancement algorithm.
15 0
Stroke weight
Bit Position (#) = Stroke Weight
0 = Reserved 8 = “Book” or “Text” Weight
1 = Ultra Thin 9 = Semi-Bold
2 = Extra Thin 10 = Demi-Bold
3 = Thin 11 = Bold
4 = Extra Light 12 = Extra Bold
5 = Light 13 = Black
6 = Demi Light 14 = Extra Black
7 = Semi Light 15 = Ultra Black
Note Only stroke weights greater than the stroke weight of the
font can be provided using the pseudo-bold enhancement
algorithm.
2-48 Printer-Specific Differences