“But — it looked great on my monitor!” : the sequel
Last time, we talked about resolution as it relates to print vs. web image reproduction. This time, we’re going to talk about color world.
Your computer monitor creates color using light, like a television screen, using the RGB or red, green and blue model.
The print world creates color using pigment. Full color images are commonly rendered using the CMYK or cyan, magenta, yellow and black model, but some high-end print shops use the Pantone Hexachrome model which adds orange and green to the color mix. Items might also be printed using spot colors (such as those defined in the Pantone matching system), metallic or iridescent inks, or varnishes that give particular visual effects. In addition, the color and reflective quality of the paper affects how a printed image looks.
What this means, simply, is that the colors in your document do not look the same on the screen as they do on the printed page.
In fact, the colors in your document might not even look the same from one monitor to the next – equipment age and manufacturing differences can cause a great deal of color variation in individual monitors.
Similarly, if you print your document on your color office printer (which probably uses the CMYK model), you may not get the same results on a different office printer, or with a professional printer.
If your color requirements are not strict, you may never run into a problem. The sky looks blue on your monitor – it looks blue on your printout – no problem! But there are a couple of common pitfalls when moving an image from the monitor where you do your layout to the printed page.
1. Dot Gain
“Dot gain” refers to the tendency of printed dots to spread as the ink soaks into the paper. This is particularly noticeable on newsprint, which is uncoated and very absorbent (as anyone with a puppy can attest!). If you are preparing something to be printed on newsprint – such as an ad – for the image to look right on the paper, it will probably have to look too light on your monitor.
Images on your monitor are luminous – lit up. Images on paper are not. This can make printed images look too flat and dark if you are expecting them to look like the image on your monitor. Again, making the image appear too light on the monitor can give better results on the printed image. Using a coated paper stock or a varnish can increase the apparent luminosity of a printed image. Sometimes shifting the color mix toward yellow or green can make the image seem more luminous.
When going from screen to print, if you are having the image professionally printed, your printer may have some good ideas about how to improve your results.
When going from print to screen — for example, if you want your website to look like your business card — you will want to talk to your web designer about how to get the best results.