Friday, August 19, 2011

Why Can't I Send A Print To My Lab?

Wow ~ it's been a busy month since I last posted, and a lot has been going on. While thinking about a new topic, I came across a couple emails from some of my client dentists asking why their labs were rejecting color prints for shade-matching, or why their percentage of re-makes were so high when they tried to use prints. A color print, quite obviously, is is a poor tool to use to convey color information to a lab.

But why should this be? After all, you have a fine digital camera and a good lens, and even an excellent color printer. The problem is not in your equipment, but in the print itself and the process of making it. Think of the limitations of that color print: for starters, it holds only a fraction of the color information that you saw on your computer monitor. An ink-jet printer, even under the best of circumstances, cannot reproduce the RGB gamut of your monitor. Plus, there is an enormous range of quality in ink-ink jet papers themselves: cheap or expensive, glossy, matte, and so on; and this all greatly affects print quality and consistency.
Now think about the process you go through to make that print. Your eyes are making decisions based upon what they see in an environment that exerts a lot of influence upon those colors. Not surprisingly, none of those conditions exist in the lab where they're trying to make sense of what you sent them. This is a truly complex subject; my most popular workshop is a 4-hour powerpoint lecture & hands-on that deals exclusively with this!

Clearly, your lab needs that color information provided by some other means. Most labs I work with prefer the images be emailed to them as jpg's. Some are requesting the dentist to actually send the CF or SD memory card itself (to be returned & re-used) so that the technician can open those images on a color-calibrated monitor in a tightly controlled color environment. If you're going to email the images, make sure you check with your lab on how they prefer them to be sent. They may have preferences on size and format, which they'll instruct you on.  Ideally you'll include in the image the shade tab and a neutralizing tab, which further help the lab determine accurate color and shading (as in the samples you see here). But make sure you don't try to "tweak" the image before you send it on. Remember, their monitors are calibrated to ICC standards -- yours are not! But more on that in a later post.

Want more info? Send me an email. And you can tweak it all you want!