Thursday, September 1, 2011

6 Printing Tips in Corel Photo-Paint: Part 1

By: Nathan Segal 

Printing is a challenge in computer graphics, largely because there's a tremendous difference between screen-based graphics and what you see on paper. This section offers tips that you can use for your home or office printer and provides additional information in case you choose to use an imaging professional.

1. RGB to CMYK
Colors that work in the RGB color space are often out of gamut in the CMYK color space; meaning that what you see on the screen cannot be printed using color inks. Other print issues are different RGB spaces among scanners or monitors, a different CMYK space among printers and printing presses and your monitor going through color shifts as it ages.

2. Use a Commercial Printer
If you choose to use a high-end commercial printer, do all of your work in RGB. DO NOT convert your print files to CMYK. If you're doing high-end art repro, you can send your RGB files and they'll do the conversion for you but expect to pay big bucks.
If you're going to a local copy center, you'll need to convert your files to CMYK yourself. If you send them RGB files the results are likely to be unpredictable.
It's important to realize that converting your files to CMYK will cause you to lose a great deal of color data. Worse, if you manipulate the images after converting to CMYK, the color data loss could posterize your image.
Ask your printer for their color profile and a print that you can use to calibrate your system to theirs. Also, be sure to ask them what file format they use and guidelines for output. This information varies from printer to printer.

3. More Control
If you want more control over the CMYK process, check out: "The Complete Guide to Digital Color Correction." This volume explains how we see color, what the differences are between human and camera perceptin, and how to work with a color wheel. You'll learn about display issues, including monitor calibration and resolution, color palettes, and consistency across varying platforms, operating systems, software and more.

4. Page Layout
Check your layouts and make sure electronic documents match the printed page size otherwise you could get an unpleasant surprise later.

5. About Graphics
When manipulating graphics, I recommend the use of an image-editing application such as Photo-Paint. Don't use these functions in Draw because this will add to processing times when you send your files to a commercial printer. Instead use Draw for page layout only.

6. Screen vs. Print Resolutions
You will need to use different resolutions depending on the final output. As an example, screen resolutions, gives you an image size of 72dpi; whereas for printing, you need to use a resolution of 125 - 400dpi, depending on the final output.
Note: Don't use screen images as they are only 72dpi. They might look great on the monitor but the printed result will be highly pixelated and will lack sharpness and depth.