Compensating for loss of colour on uncoated stock

[YooDooRight]

Im aware that colours never look as bright or as 'punchy' on uncoated stock. Im producing a cd cover on uncoated white card that features a sticker on the sleeve that'll be printed on coated stock. Both elements feature the same blue colour (c90/m30/y0/k3) that i picked from a process colour manual (coated paper only!). Obviously the two elements will vary in shade due to the different paper finishes but are there any compensations i can make to the uncoated colour mix to get it brighter and closer to the coated swatch book and cover sticker?

I'm hoping theres some magic trick of the trade here ;-)

Thanks

YDR

[Broacher]

A small +3 to +5% adjustment to your RGB>CMYK profile setting will help reduce the 'darkening', but nothing beats a sample to match. Do you have any swatch books at your disposal?

[YooDooRight]

The only swatch books i own are a Pantone Solid (coated + uncoated) book and a coated CMYK process swatch book neither of which help me with uncoated cmyk mixes ;-(

will try the percentage increase.

Thanks.

[YooDooRight]

more alarmingly... my c90/m45/y0/k3 mix is looking rather purpley on my (apparently!) Huey calibrated monitor wheras in the process swatch book it's a nice rich blue.

What do i trust?

YDR

[Broacher]

I should have clarified that I'm talking about dot gains, but I figure you know that.

What makes CMYK matching across different stocks even more difficult is that not all CMYK inks are equal, mix equally, or are even laid down in the same order --though on the same press, the same printer, for the same job, this should be a given. Which is why I would be sure to talk to the printer about being there for a press check and explain, in detail, what you're trying to match. Some blues are notoriously difficult to match between coated and uncoated. And there's better than a good chance that they have a much more complete ($$$$) set of swatch books at their shop which you may be able to consult for matching the mixes. Something like this: http://www.graphic-design.com/DTG/Reviews/tintbook.html

(Wish we had that set!)

That K3 will be the bugaboo, I bet. At 3%, it's right on the edge of disappearing, but so critical to the final match. My guess is that you're going to need to balance that on uncoated by eliminating black altogether and seeing what tweaks to the CM mix on your uncoated stock will do for you.

Good luck!

[YooDooRight]

Okay, so dot gain is key.. i guess as i'm printing on uncoated stock it's a major factor here. So im fairly new to dot gain and have read a few chapters on it which i now need to put into practice.

New question... Im also calibrating a black and white image for the uncoated cover of this cd case and have understood (correctly?) that i need to leave a buffer zone each end of my k percentages to avoid dissapearing dots, about 10% for uncoated stock.

So in practice this means my tiff image has no k values more than 90% or less than 10% and at print my highlights and shadows will naturally brighten and darken slightly through dot gain corrrecting the images contrast... is this right?

Also, if im embedding a colour profile that already allows for 10% dot gain, am i not repeating myself?

Thanks

YDR

[budafist]

I would go to your printer and use their uncoated swatch book to find the closest match to the sample colour you want. That or you can just discuss with them to "match sample". Often we don't even give a Pantone colour and just tell the printer to match a sample. We've had squares of fabric to match before.