HP Designjet 2000/3000cp HP DesignJet 3000/3500 CP Printer User’s Gui - Page 235

What is Banding? Troubleshooting Solving Image-Quality Problems 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: Secondary Color Red (R) Blue (B) Green (G) Primary Color Components Magenta (M) and Yellow (Y) Magenta (M) and Cyan (C) Cyan (C) and Yellow (Y) 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. 11-11