Color Picker - Question

[RTK]

The colour picker is not totally accurate, as most of you know, it miss-fires a miniscule percentage in the RGB colour model... not a big deal as far as I'm concerned.

But in CMYK Xara seems to build up the color differently when sampled with the color picker:

A base color of C=30% M=30% Y=70% K=20% is sampled with the color picker as C=50% M=50% Y=90% K=0.2%. To me these colours look the same on the screen, but would they look different if printed by a pro?

Xara seems to build up the sampled color with no or as little black as possible. - Why?
- Can you tell the difference when printed?

Thanks for any info!

Risto

[RTK]

The colour picker is not totally accurate, as most of you know, it miss-fires a miniscule percentage in the RGB colour model... not a big deal as far as I'm concerned.

But in CMYK Xara seems to build up the color differently when sampled with the color picker:

A base color of C=30% M=30% Y=70% K=20% is sampled with the color picker as C=50% M=50% Y=90% K=0.2%. To me these colours look the same on the screen, but would they look different if printed by a pro?

Xara seems to build up the sampled color with no or as little black as possible. - Why?
- Can you tell the difference when printed?

Thanks for any info!

Risto

[gwpriester]

Risto

My suspicion is the both colors would look pretty near the same.

I noticed some time ago that different software products give different percentages for the same Pantone spot color CMYK conversion.

You are better off with more color and less black. But a good balance is desirable. CMY supposedly produce black. But they don't. They produce a muddy brown. A bit of black puts things to right.

Hope this helps, some.

Gary

Gary Priester

Moderator Person

beehive or bus melt

[RTK]

... thanks, Gary!

A follow-up question: if you intend to have something printed, do you work the whole piece in "show printer colors" mode? I switched to this mode for a couple of images that I had created in "normal on screen mode" and I started bleeding from the eyes! [img]/infopop/emoticons/icon_smile.gif[/img]

Risto

[tad]

Well, you are right and wrong. When I check somewhat dark areas of an image I get plenty of K. However, I created a solid 30,50,10,20 color and Xara read it with ZERO K. So whatever the program is using for GCR & UCR is a choice it is making, not us. But LIGHT GCR "is" usually preferred.

I must say that when I checked "show printer colors", it was spot-on visually.

I recommend sticking with RGB until you really need to do advanced color correction. In fact, you might want your PRINTER to do the seps, so you can blame him for the rotten look. But, perhaps the Xara team will give us some control of the black plate in a future release. Who knows ????

Regards,,,,,,,, Tad . [img]/infopop/emoticons/icon_biggrin.gif[/img]

[Sean Sedwards]

Colours expressed in percent are only an approximation of the true 0 - 255 values. Change Utilities > Options > Units > Colour units to 0 - 255 for maximum consistency.

The three approaches for having artwork professionally printed are:
1. Design in RGB and send it to the printer for him to produce a printed version that looks like the screen. The printer therefore performs an RGB to CMYK conversion based on his (presumably) in-depth knowledge of his own process.
2. As above but do the conversion yourself in PhotoShop, say. The printer just sends your CMYK file unaltered to the press.
3. Work in CMYK in Xara X and use Show printer colours to gauge how it will turn out. Once again, you expect the printer to send the file unaltered to the press because you've actually defined the inks.

The problem with 3 is that despite what inks you define, Xara X will convert transparency etc. to RGB then back to its own CMYK interpretation of the RGB. You will only retain control over pure vector shapes and lines.

Option 2 is not bad so long as you are familiar with the printing process that's going to be used. If you just use PhotoShop's default settings you're taking almost as big a gamble as option 3.

Option 1 is my favourite. The printer will probably just pass the artwork through PhotoShop on default settings, but they'll be defaults specific to his process. You should be mindful that RGB has a greater gamut than CMYK, i.e., not all RGB colours can be printed in CMYK, but this technique will likely produce the best results.

Regards - Sean