Colour Management - Wrong Way Round

[irneb]

I've just got an Oce CS2044 (42" Plotter) ... Well actually it's a Canon imagePROGRAF W8400 with an Oc badge stuck on . I've found that without using any color matching the print comes out way to blue, while using their ICC profiles it comes out way to yellow / green. I don't mean slightly - the gray-green headres on this page will come out looking nearly neon.

So into the Color Matching Workflow I'm going ... augh This is a pain in the neck - shouldn't the matching methods work the other way round?

The way all matching programs work is to match your scanner / camera to a preset colour chart (e.g. Pantone), then match your screen to that same chart. Then print about 200 to 1000 :O prints adjusting slightly on each colour on the chart - this may take a month or more .

Most of these programs (actually all) simply save a table of correct colours referring to printer "error" colours, then the ICC (or ICM) colour matching interpolates the colours not found in the table so you don't have to save 16 million colours to cover the entire RGB spectrum.

Instead of following the hit-and-miss approach for printer mathcing above, could you not do something like the following?

After matching your scanner / camera and screen - which isn't half as difficult as matching the printer. Could you not print out a test chart of various colours (something like a Pantone chart)? Then choose the closest match (on screen - varying the Hue, Saturatiuon & Luminance to suit) to each of these printed colours - in essence telling the matching program the colour "errors" the printer makes. Then the program could simply referse these - you may have to print a few times just to fine tune :| but you could come very close in one step instead of hundreds .

Of course the more colours in your chart the more acurate your final icc profile will be.

Does anyone know of a system which could work this way?

 

[Grandad35]

irneb,

You are more or less describing how it used to be done when the entire workflow was done in one place. The main problem with this approach is that you no one else will be calibrated to your system. With a 42" printer that lists for about $6000, I imagine that you will want to print for others as a business. The colors of their images will almost certainly be off with your calibration system.

A lot of work has been done over the years to establish standards for color, and the easiest way to get your colors correct is to set up a "Color managed workflow". A good basic link on this subject is (http://www.normankoren.com/color_management.html). With a professional printer like you have, you need to become an expert on this subject, and a great book that you should study is (http://www.amazon.com/Real-World-Co...0/ref=pd_bbs_sr_1/104-0000614-4603121?ie=UTF8). It's not an easy subject to learn, but the rewards are great. It will cost you some money for a hardware calibrator for your monitor and to have custom profiles generated for your scanner and printer/ink/paper combinations, but it will cost far less than developing your own color management system when you count your time and wasted printing supplies. Compared to your printer, the calibration hardware is cheap.

 

[irneb]

Thanks for your reply. I've asked Oc if they can sell us such a colour management system, but still waiting for an answer after 2 weeks.

I've been going through your links in this forum, and have come to the same conclusion - we'll have to invest on a Workflow system.

I don't think that we require an absolutely acurate matching - as we generally don't print photographs. We're an architectural practise printing 3d rendered drawings produced in AutoDesk Revit or SketchUp and adjusted in CorelDraw or PhotoShop for presentation purposes. Thus we only want it to look presentable - i.e. matching to what we've got on screen makes this easier as we adjust the rendering there first - then print. We do have about 10 PCs that print to this printer (connected on LAN) - could become more later but at the moment not everyone does rendering.

We probably will go to a more acurate system, but just don't have the time at present.

 

[Grandad35]

The last time that you were in a store that had rows of TVs on display, did you notice how the same feed gave wide differences in the colors? The same thing happens with computer monitors. Your system will (at a minimum) require that all 10 of your computer monitors be calibrated to give the same colors on the same image. You might be able to get close manually, but you will never do it as well as even a low cost hardware calibration device (e.g. http://www.chromix.com/ColorGear/Shop/Productdetail.cxsa?toolid=1119).

A hardware calibration device has these additional advantages:
1. As a business, your time has real value - hardware monitor calibration only takes a few minutes (once you learn how to do it), and will be far quicker than manually tweaking.
2. Monitors change their colors as they age. It is recommended that you periodically recalibrate them to maintain color accuracy.
3. With calibrated monitors, you will have already taken the first step toward a standard color managed workflow, if you ever decide to go that route.
4. With calibrated monitors, you will know that your images will display properly on the monitor of anyone else who has a calibrated monitor. You will also be able to have your images printed by outside sources.
5. If you can get your printer calibrated to match your monitors (not an easy thing to do), there is a good chance that you can print similar artwork from other sources, as long as their monitors are also calibrated.

 

[irneb]

Thanks, you've convinced me ... now just to convince the directors that they've got to scratch in their back pockets again