Tips for Successful Plotting

Overview

Printing to the large-format RCS plotters can be oddly tricky at times. This document provides some useful tips for successful plotting. 

Important Notice:

For the Spring 2021 semester, due to COVID-19 related restrictions, Operations will not be able to run the plotters as fast as we would like.  During periods of heavy usage, you should plan on having to WAIT SEVERAL HOURS before your job even begins to plot.

Procedures

Resolution Tips

Note that, although the maximum resolution of the HP DesignJet series of plotters is 600 DPI, you should create your graphics at 300 DPI rather than 600 DPI. The result will look just as good, and you will avoid problems caused by the huge job data-file sizes of 600 DPI graphics. On the other hand, if you have created graphics at screen resolution (usually 72 or 75 DPI), they will not look good when printed, no matter how high the resolution of the printer or plotter.

Use of Background Colors

Solid backgrounds use a tremendous amount of ink, and there is no guarantee that the result will be satisfactory. If your plot is large and has a solid color background, you may not like the result due to the saturation of the paper. It is also possible that the plotter might run out of ink before finishing the plot.

In addition, because the paper becomes so saturated with ink, it often will take significant amounts of time to dry enough before it can be rolled up.

Color Matching

For many reasons, it is extremely difficult to make your plotted output match the colors you see on the screen. For starters, monitors and scanners are based on an “additive” color system, using the RGB (red, green, blue) color space, while the plotters are based on a “subtractive” system and use CMYK (cyan, magenta, yellow, black). And different monitors can vary in many ways, including calibration, variances in the phosphors and bit-depths. Also the device gamut (range of colors) is widely different, with monitors displaying many more colors than any printing device. Colors will also look different on different types of paper. Color science is exceedingly complex — way beyond the scope of this discussion. Although the section on configuring the plotter device driver and the section on plotting from Photoshop have a few tips for improved results, the bottom line is that you cannot expect exact agreement between your screen and the paper. If precise color rendition is important to you, consider going with a professional printing outfit.