One of the issues a sign shop may encounter when printing wide format is banding. Banding is a defect in printing that appears as streaks or bands in the printed output. There are a number of possible causes of banding. An understanding of the causes can help eliminate waste and ensure your printed output looks its best.
The first step to solving banding is to classify the type of banding. This might include uniform dark or light banding, gradient and chromatic banding. The causes and solutions for each are presented below.
Uniform Light Banding
Light banding can be caused by incorrect media feed adjustment (printing gaps), inoperable printhead nozzles, or incorrect heater settings for the media being used. Use your printers print test to verify that all nozzles in the printhead are firing. If there are gaps, use the printer’s cleaning menu option to clean the printhead. Your printer will have a menu option for adjustment and calibration that can be used to adjust media feed. If the printhead is clean and media feed properly calibrated, try decreasing the temperature of the print heater and dryer by 5 degrees Celsius.
Uniform Dark Banding
Dark banding can be caused by incorrect media feed adjustment (printing overlaps), inoperable print-head nozzles, or incorrect heater settings for the media being used. Use your printers print test to verify that all nozzles in the print-head are firing. If there are gaps, use the printer’s cleaning menu option to clean the print-head. Your printer will have a menu option for adjustment and calibration that can be used to adjust media feed. If the print-head is clean and media feed properly calibrated, try increasing the temperature of the print heater and dryer by 5 degrees Celsius.
Gradient Banding
Gradient banding is not caused by the printer, but the file being printed. Gradient banding can occur in vector based gradients, and can be solved by rasterizing the file in Photoshop with at least 100 ppi and adding a small amount of distortion such as Gaussian blur to smooth out the steps in the gradient.
Chromatic Banding
Chromatic banding appears as alternating light and dark stripes of color. This is the result of inverting the order of ink being laid down in bi-directional printing. This type of banding is most common in dark, solid colors being printed with UV cured inks. The solution is to print the file uni-directionally.
For more information, contact:
Spectrum Signs
23382 Madero Suite L
Mission Viejo, CA 92691
(949) 297-3800
