by Steve Upton
I think it's about time to talk about workflow.
This article got a little long but when I tried to break it in half for next month I couldn't find a place that wouldn't make me frustrated if I were reading it myself. I always hated that "...to be continued" bit just when the show was getting interesting. So, here it is in all its mass.
Workflow, really, is where I find most people wanting to know the answers. This rubber-meets-the-road part of color management seems to where people start the journey of managed color and the majority of questions in our speaking and training sessions fall in this area. People really just want to know how to make this stuff work.
I always say that you only need two things to have good color: great profiles and proper use of them in your workflow. Even with perfect profiles, improper use of them will create frustration for you.
It helps to understand how all this stuff is to fit together if you start with some basic ideas and strategies:
- Anything that comes from a device will be in that device's color space and images headed out to a device should be in its color space. This means that your scanner is going to give you ScannerRGB and your monitor, printer, and press should be handed YourMonitorRGB, YourPrinterCMYK (or RGB) and PressCMYK respectively. These device-specific numbers are the reason why we build a good profile for each individual device.
- The location in your workflow where the conversion from one set of settings occurs (say ScannerRGB to PressCMYK) is changeable and will probably depend on your business, equipment, funds, time and other factors. This flexibility is powerful but contributes to the confusion surrounding color management.
So, let's take a hypothetical example of a scanner, monitor, printer and press. You would like to scan an image, have it look good on your monitor, separate it to PressCMYK, soft proof it on your monitor, and then hard proof it on the printer. Sound familiar?
Looking at just one of these conversions, ScannerRGB to PressCMYK, we see that we can do it many different places: RGB->CMYK in the scanner software, in Photoshop, in QuarkXpress, in the printer driver, in a color server, or in the RIP.
No wonder this stuff is so confusing!
I have counted 4 different ways of doing the conversion in Photoshop alone!
It is important to realize that after the file is separated to PressCMYK it needs to remain unaltered for the rest of its journey to the press. Although it may take side routes to the monitor and printer for proofing, your color for the press is done.
The best method to deciding what is right for you is to use the following criteria:
- Not all conversion points are equal. I trust Photoshop 6 more than most other applications. Photoshop 6 will allow you to perform all the conversions mentioned above with good results. It is wise to test your profiles in this manner. When you are happy with the results, then try applying the conversion elsewhere with the same profiles. If things mess up, you know that the application or RIP you added to the mix is causing the problem.
- If you use Photoshop a lot in your workflow and it is just as easy to convert colors in Photoshop rather than somewhere else (as is often the case with scanner software vs. Photoshop), then use Photoshop.
- Leave your images in RGB farther along in your workflow (like after page-layout for instance) if you are going to send the document to multiple media. Going to CMYK too early in your workflow will result in a file that is good for one purpose but requires reworking for all the others.
- Workgroups can complicate things with the need to keep everyone trained and up to date but they can also benefit from workflow tools as I'll explain below.
Most workflows can be roughly divided into single/raster image and composite/postscript images like created with a page-layout application.
In the single/raster image situation you have, for example, a great TIFF file that does not need to be joined by any other elements. Printing these files directly from Photoshop is usually the best course of action. You can either apply the profiles "by hand" in Photoshop using the "Convert to Profile" command or allow Photoshop to perform the conversion on the fly as you print.
When you have composite/Postscript images, like a brochure composed in QuarkXpress, then your life becomes quite a bit more complicated. One single file can contain TIFF's, EPS logos, and QuarkXpress elements (boxes, etc). QuarkXpress 4.1 does have some color management capabilities built-in but cannot manage embedded EPS files and does not allow all the control over color conversions that you may need.
For our example, say we have such a file and we would like to view it on screen (soft proof), print it to our printer (hard proof) and then send it off to press. If the job is only intended for press then I typically suggest that images be converted to CMYK prior to placing in Quark. This also fits most traditional workflows.
To soft-proof to screen, Quark needs to be set with the correct PressCMYK profile and your monitor profile. With the image previews set to 32 bits Quark will do a fair job of proofing to screen but EPS images are still unhandled.
Hard proofing is simply not going to work with Quark for our example due to the EPS problem.
Sending the job to press will work fine however as it's all in PressCMYK and was separated properly in Photoshop.
So what about the hard proof problem? This is an example of several places in today's workflows where color management breaks down due to applications not fully supporting all the features we need. Feel free to bug Quark about this one next time you have their attention, we all need this to work properly in version 5.
There are three solutions to this problem.
- CompassPro XT is a Quark-specific solution that comes in the form of a Quark Xtension. CP XT allows you to setup the conversion preferences and then interrupts the printing process to convert the document elements on their way out to your printer. It works well but only for Quark and you will need a copy for each member of your workgroup.
- Get a RIP for your printer that will allow you to load the PressCMYK and printer profiles and will perform the proofing conversion for you. This is becoming the most popular choice in digital prepress proofing today. A good RIP will do this job quickly and accurately and this will avoid the need to do this on each machine in a workgroup.
- The most powerful and flexible solution is a color server. Color servers are applications that reside on a server (not necessarily dedicated) on your network and perform color conversions for your whole workgroup. Most color servers work at minimum with hot folders, processing files dropped into one folder and placing the results in another. You can setup print queues to appear on the network and forward the resulting files to printers, RIP's etc with your existing server software. A full-featured color server will setup its own queues and hand off the files for you.
Color Servers have notable advantages over Quark plug-ins and in-RIP proofing:
- They do their color conversions well, not all RIPs can be relied upon for this.
- They typically have more options for handling RGB files, vector colors, and rendering intents
- The resulting files do not necessarily have to go to a printer. A PressCMYK PDF for example can be quickly converted to sRGB for serving on the Internet. You can also use them for preflighting files by dropping the entire job in a folder and having the server find and separate any RGB files to CMYK using high-quality, reliable settings and profiles.
- The output can go to multiple printers of different types. While a proofing RIP will handling one or two printers well, a color server can take the same PressCMYK file and send it to your inkjet proofer, color copier, and large-format inkjet on canvas and get great color on all devices. This may sound like a dream come true but I assure you it is being done successfully today. RIPs that you are forced to use (like for copiers) but have poor color management capabilities can have their problems bypassed by performing the conversions upstream in the server.
- Non publishing applications like Word, PowerPoint and Excel can be handled properly so you can stop fighting those purple presentations.
There are other benefits of servers but these are some of the most significant. Suffice to say that if you are finding a break in your workflow due to some finicky software, a color server can probably be used to work around it.
Some feel color servers are simply a temporary solution until the OS, applications and RIPs get up to speed with color. I think this is partially true but they have other benefits that will continue make them valuable. Either way we have several years ahead of us before things are updated to the point where you would shut one down and in the meantime we all have better things to do with our time no?