We have used a Gerber Edge since 1996 to print spot colors for use in interior graphics, decals, logos, etc. We never used it for printing full color (process) images because we found the output unsatisfactory and the exterior longevity of the prints lacking. We used a solvent printer for those.
I'd like to use the Edge to print small four color images occasionally, and would like to know the best way to set up the image to get the best output. File type? Edge setup?
We recently upgraded to Omega 6 and have an Edge II. Running our first job at 600 x 300 dpi, which we couldn't do before the upgrade, has me optimistic that we can print small images for boats, trucks and small signs.
But I don't know how to set up the file for best results.
I hope someone here can give me a good starting point.
Process color printing is much different from spot color printing. It has its pros and cons.
Outdoor longevity is greatly enhanced by overprinting with a clear UV/Abrasion Guard foil for both process and spot colors. We have been using the
Apex version available from Advantage Sign and Graphic Solutions for years with great success.
To improve the quality of process prints, you will need to get more familiar with halftones, Lines per Inch (LPI) settings and color management. Because process printing is done with percentage mixes to achieve its colors instead of solid spot colors, there will almost always be halftone dots visible to the naked eye. With proper setup, however, you should be able to get better than satisfactory results. One benefit of process colors vs. spot colors is that there is no need to deal with chokes and spreads or traps as one does often with spot colors.
Halftones are the first item to discuss. These are the dots used in mixing CMYK foils to achieve any given color. Gerber gives you a number of halftones from which to choose which are varied in their shapes, dot sizes and operator control. They can be varied from large to small and will modify the tonal quality and the fineness of the print as they change. For example, when a gradient or shadowing is present, it will be most pleasing to the eye when tonal quality is high and banding will appear as more fineness is introduced. But the price you pay is that the size of the halftone dots will be larger and more noticeable. Increasing fineness reduces the size of the halftone dots but with a loss of tonal quality. It's great for solid colors and generally improves photographic prints as well. Generally speaking Gerber Tone and Gerber Tone Fine are automated with no control over what you get. Settings for tonal quality to fineness (LPI) are done automatically and are based on the size of the print. I prefer Classical Dot for vectors and Gerber Tone STC Photo for images because each allows the operator to insert LPI settings manually.
LPI (Lines per Inch) settings will modify the halftone dots from large to small - coarse to fine and, as mentioned, will modify between tonal quality and smoothness. There are three settings I use the most because they supposedly match the harmonic frequency of the print head. They are:
42.4 - Coarse print with excellent tonal quality.
53.0 - Medium print with satisfactory tonal quality.
70.7 - Fine print for solids and most photos and images.
Color management is a broad and complex issue that deals with the various color profiles and color settings in your system. This discussion is limited to only two issues for now.
1. Color Mode: Generally you will be choosing between CMYK and RGB for the color settings in your file. Although it may seem intuitive to set your colors to CMYK because you will be printing in CMYK, the fact is that the results are often flat and lacking in vibrance. RGB will give you a wider color gamut and is preferred by this writer.
2. Output Color Profile and Automatic Color Management: When you get to GSPPlot, click into the 123 Print Options dialog (F11). Uncheck the box for "Color Correction" and choose the profile to be used from the drop down menu. I recommend the profile named Gerber EDGE II 300 DPI CMYK. Simply put, it is the best all around profile in the Omega software.
Do some test prints using the different settings and come back to this thread with questions or input.
