Resolution Explained

Resolution is an important part of not only the printing process, but also the pre-printing process.

Digital printers require digital images in order to print. In order to maximize print quality, it is important to understand the resolution of the image being sent to the printer as well as the resolution settings the printer prints at.

The 1170 printer has two resolutions it can physically print which are 1200x1200DPI and 1200x600DPI. DPI stands for Dots per inch which essentially means how many droplets can be fired per 1 square inch.

The first number (1200 x 1200) indicates the resolution across the print bar. As the printer has a fixed number of nozzles (59136 to be exact) the resolution across the print bar is fixed.

The second number (1200 x 600) indicates the number of droplets in the direction of belt travel. This number can be lowered in order to achieve faster print speeds and lower processing time.

As you can see in the above image, when printing at 1200 x 600 dpi we are printing every other drop. Note that the above picture is a very scaled up image. Even when printing in 600 dpi in the print direction, there are still nearly 24 droplets per 1mm.

When using the windows driver or Xitron rip, it is also important to understand the resolution of the digital images that are being sent to the printer. The printer accepts three different resolutions as follows:

Note: The Xitron DFE shows the digital image resolution - not the printed resolution

Best Quality (Plain Paper 600 in Xitron DFE)
sends 600 x 600 image to printer and will print 1200 x 1200 DPI

Normal Quality (Plain Paper 300 in Xitron DFE)
sends a 300 x 300 image to the printer and will print at 1200 x 600 DPI

Draft Quality (Plain Paper 150 in Xitron DFE)
sends a 150 x 150 image to the printer and will print at 1200 x 600 DPI

While lowering the printed resolution from 1200 x 1200 to 1200 x 600 will have some print quality differences, it is important to note that the ink usage will be very similar. This is because ink density is limited when printing at 1200 x 1200 much more than it is limited when printing 1200 x 600.

The main quality difference comes from the pixilation that occurs when sending a smaller image.

For this example, we will zoom in to one of the octopus arms at 600x600, 300x300, and 150x150 pixels per inch:

As the resolution goes down, information on what to print is lost. This leads to pixilation and noise being introduced to the print quality.

600 x 600:very crisp lines, only two colors visible are really orange and black.

300 x 300: lines start to get a little blurry, around the edges more colors are introduced such as grey and shades of orange.

150 x 150: Lot of pixilation and Jpeg scaling (pixels becoming off colors).

These defects will be translated to the printer which is why it is important to understand the image resolution on the artwork as well as the print settings.

Below shows the print quality of these three different areas. Note that the two right images are printed at the same resolution, but due to the lower input image resolution, more noise is introduced with the 150 x 150 input resolution.