HP Designjet 2500.3500cp Printer series - Manual (Page 231)

Troubleshooting
Solving Image-Quality Problems
11-11
What is Banding? Banding is when you see repetitive horizontal bands within your printed image
(these may appear as light or dark bands).
The test pattern is printed with four primary colors; black, cyan, magenta and
yellow. The three secondary colors printed are; red, blue and green and they are
formed by mixing the primary colors as shown in the table below:
Solving the Problems
The main causes of banding are:
n Printheads
n Media advance.
Banding Caused by Printhead Problems
If the test pattern has clear or dark horizontal bands in one or more of the primary
color columns, then several of the secondary color columns will also have the same
type of bands in the same position (but perhaps with less intensity).
These bands are caused by two types of printhead nozzle failure; either nozzles not
printing, or nozzles misdirected. See page 11-16, Nozzle Print Test for more
information.
In the following Example A , several nozzles in the magenta printhead are not
printing. There will be clear repetitive bands (perhaps white) in the magenta
column. Consequently, you will see lower intensity bands in the same print position
in the red (M + Y) and blue (M + C) secondary color columns.
Secondary Color Primary Color Components
Red (R) Magenta (M) and Yellow (Y)
Blue (B) Magenta (M) and Cyan (C)
Green (G) Cyan (C) and Yellow (Y)