Banding can occur in an image for a number of reasons. Typically it occurs due to groups of nozzles that do not fire or that fire with poor directionality. This can occur if the printer sits idle for an extended period of time, or if debris has been picked up from the media or table and deposited near a printhead. If banding is evident, print a nozzle check to identify which nozzles of a particular printhead are not firing. Perform Automatic Printhead Maintenance to clear the affected printheads. Print another nozzle check to confirm whether the problem has been fixed.
NOTE
Keep the table surface clean and ensure the media is clean and free of dust to help reduce banding. Use an anti-static brush, if necessary. Also use a micrometer to accurately measure the media thickness so the proper printhead gap between the printhead and the media is used. If the printhead gap is less than it should be, there is a greater probability of picking up debris on the printheads
A clogged nozzle may not recover by performing Automatic printhead maintenance. In this case it is recommended to recover the nozzles by swabbing (see the section: Recovering Nozzles by Swabbing)
If a print still shows banding after the procedure for recovering nozzle outs documented in the Maintenance chapter, consider using a higher quality print mode to reduce banding. If banding continues you may need to place a service call as the cause may be mechanical.