Gray level refers to the nozzle can spray different sizes (diameter, volume) ink droplets according to the need in the same nozzle .
The gray level of the nozzle is divided into 4-8, this classification represents the composition of the big ink droplets, 4 is that: big droplets consist of four small droplets, 8 is that: big droplets consist of eight small droplets.
How it works: In the same nozzle of the printhead, by controlling the vibration of the piezoelectric body, to spray one or more small ink droplets in a very short time, small droplets can be aggregated into a big ink droplets.
For example: a 14PL nozzle, to print with 8 levels gray, That is the composition of eight 14PL small droplets, The size of the ink droplets is equivalent to the 112PL ink droplets, and 4 is equivalent to 4 * 14 = 56PL ink droplets.
When printing a product with dark and light color, the gray function is very important, the following talk about [no gray level function], [with gray level function], [gray level + drop variable] In the application of the transition when printing.
No gray level function, the ink droplets sprayed by the nozzle is not composed of small droplets, such as 14PL nozzle, it is the size of the ink droplets can only be 14PL. It is only possible to reduce the printed pixel density (DPI) when printing lighter areas.
With a grayscale function, you can eject smaller droplets to show light colors, and the density of the pattern (dpi) does not change.