Colour and VectorWorks

[Christiaan]

Over the years we've had issues with colour synchronisation (between our screens/VectorWorks and our Epson 7600) that have often been a bit of a mystery (e.g. a green tinge to prints). The whole topic seems very complicated.

So with the advent of commercial colour charts in v2008 I thought I'd try and understand the process better, so...

1) Can someone point me to a book or PDF or website that does a good job of shedding light on the whole topic?

2) Should VectorWorks output be thought of as CMYK or RGB, or something more complicated?

3) Should we think of our Epson 7600 as a CMYK device or a RGB device, or something more complicated?

4) Do any of you use the Colour Management in VectorWorks print driver (or ColorSync)?

5) And why to paper settings in the 7600 seem to have such a huge effect on the colour printed output?

[islandmon]

Basically, the Display utilizes RGB whereas the printer requires CMYK .. hence the need for translation which becomes especially problematic with transparent Alpha Channels designed to enhance the Display's fidelity.

All Inkjet type process printers are CMYK and for obvious reasons they generate process colors like Pantone.

ColorSync is a configurable software solution designed to bridge the translation gap between What You See on the Display ...and... What You Get from the printer. There are various Colorimeters available to test the Display and calibrate the CMYK output for the limitations of the printer's PPD. These are mostly used by high-end publishers for 1200-2400 dpi where shading & bleeding is a significant issue.

Paper settings matter because of the rate of saturation, absorption, and reflectance of the 'egg shell' coatings.

[brudgers]

As mentioned what you see on the screen is RGB what you get from your printer is CYMK (typically...with a four color system, though many printers now have more colors).

The printing process is dependent on paper type, that's why there are Pantone gamuts for both coated and uncoated stock.

Pantone Process color is not CYMK...it uses 14 proprietary inks. CYMK gives a reasonable approximation of many process colors. Pantone also has a CYMK gamut that you could use to calibrate your printer...and some printers are Pantone certified to produce certain colors accurately.

Unless you're doing work for print media, what you get out of the box is probably good enough for most applications...and if you're trying to do print media work using Vectorworks you probably deserve whatever results you get.

The gamuts for RGB and CYMK are very different and therefore the range of colors which can be accurately produced by both is limited.

If you're really intent on research just google up "color gamut" and enjoy.

[Christiaan]

Thanks guys And have either of you used the colour management settings in the VectorWorks print dialogue (or ColorSync)?

The reason we need reasonably accurate colour is for elevation drawings produced for planning applications. The more accurate we can be with this the smoother the process of getting planning permission can be.

[brudgers]

The realworld is neither RGB or CYMK...it's full of water vapor and dirt and it's really big compare to a sheet of paper...so accuracy in those terms is a fiction...and probably not what the planners want to see anyway.

You can calibrate all your various pieces of hardware for consistency. And you can tightly specify the color of certain objects using standards such as RAL. But you can't accurately recreate the impact of a 20,000 sf facade on paper...even if your local government wants to pretend that this is possible.

I would favor artistic vagueness over virtual reality. You're selling it to the planners anyway.

[Christiaan]

Agreed vagueness can be a good thing when it comes to planning (hence "reasonably accurate" colour). But there's very little point in using the commercial colour palettes in VectorWorks if the colours on your screen and printed out don't match the swatches to some degree.

The less we have to manually fiddle with colours in VW to make them represent what we say they represent the smoother the whole process and the faster it is to make changes.

I take it you haven't used the colour management settings in the VectorWorks print dialogue?

[billtheia]

I haven't tried to control color in VW but I have tried it in Adobe Illustrator - It's a giant can of worms.

Your first problem is, as has already been mentioned, getting an RGB monitor to display CMYK colors with any accuracy. This generally involves using some type of color calibrating device. I doubt that these devices (at least the ones that you might be able to afford) are perfect. They're probably better than nothing, but at what cost?

THEN you need to get your PRINTER to accurately print CMYK. You'd think that it would be a pretty easy thing to do - they are CMYK printers after all - but the level of accuracy that you get out of an inkjet printer can vary pretty widely. You can usually adjust the output via printer driver but in most cases, making one color more accurate, makes another less so.

So, in the end, it is VERY difficult (if not impossible) to crate a truly accurate system that would allow you to pick a "known" color and have it render accurately on the screen and in a print.

Add to that the real world atmospherics mentioned above and the effect of light and shade on different sides of a building, and you discover that color accuracy is a myth.

In the end, if getting really close is important, you're probably best off picking a known color in VW and adjusting your printer driver to try and match a physical chip. This really only works on flat elevations and it means that you'll be adjusting color on every job.

Good luck.

[Christiaan]

What we get on our screens is pretty good actually. It's mainly the printing that we have problems with. I might have a play around with the colour management tomorrow... I was thinking that our printer might have some inherent and consistent bias so that once we've adjusted the colours in the colour management window correctly we could use that setting from then on.

I'll let you know how it goes. Thanks for all the advice.

[brudgers]

C,

I don't really need to closely calibrate the colors. I run a check print and adjust as needed.

Printed color varies too much with media and device...besides I always want to change something after I print it.

Calibrating all the components (printers, monitors, and scanners) just seems like more trouble...since I really only care about the printed output.

[edit] With a standard monitor under standard lighting it is virtually impossible to correlate with printed output becuase the difference in the way the images are lit.

Edited February 27, 2008 by brudgers

[RGyori]

I don't have full the technical understanding of all of the issues involved but I am in the process of calibrating my monitor and printer in order to control and make consistent the color prints for my photography.

I use a Datacolor Studio system (not too expensive and there are several competing products available) comprising software, a spectrocolorimeter to calibrate the monitor and a colorimeter to read and calibrate printer output. The former produces a custom ColorSync profile for your monitor and the latter a custom ICC printer profile for the particular paper you intend to use. Straightforward processes in principal but very much an iterative ones in execution. I have achieved the beginnings of some consistency but more time and experience will be required before I am satisfied. I print my results with an Epson 2400 via Photoshop CS3 that plays well with custom ICC profiles though I have not yet tried the same printing from Vectorworks.

I hope this may shed some light on the subject.

Bob