Pantone to CMYK Conversion (Help)

[djb]

Hi folks, I need a bit of help trying to convert a colour to CMYK. I don’t have the relevant Pantone to CMYK book so just went with switching the colour to CMYK in Illustrator. Have then output a proof and the colour (320) has come out really blue on two different printers whereas on screen it’s still the correct shade of Turquoise.

Does anyone have a Pantone Book and can give me the correct reading? I’ve had a look on t’internets and am getting all kinds of different numbers back.

Thanks in advance.

[SparkCreative]

100c, 0m, 30.5y, 6k

[djb]

Thanks. That’s roughly what I’ve got. Maybe it’s just the printer although it’s strange it came out blue on two different ones. Perhaps it’s just one of those colours inkjets hate!

[SparkCreative]

Could well be. Inkjets are a bugger to get calibrated properly - you've got Adobe software trying to colour manage it and then usually the printer software too. Lots of trial and error necessary. Have fun.

[squeezee]

The CMYK to Pantone conversions are based on the SWOP icc profile I believe, which is offset inks. Those are not the same as the inks in your inkjet and thus they won't give the same colour.
Pantone colours are defined in Lab colour space and converted to CMYK for your printer or RGB for your monitor by using your output and working profile. You need to calibrate your monitor to see the colours correctly, work in a neutrally lit room wearing grey clothes etc.
Your printer should be calibrated and profiled.
Even then, some colours will lie outside the gamut of your printer, please don't be surprised if things don't add up.

[djb]

It’s the devils work. I’ve printed it out numerous times now on numerous different stocks and come to the decision that there must of been some colour profiles doing strange things on my original PDF as all the tests I’ve done look pretty much right.

One day I’ll get my head round colour profiles, until then it’s off to the Pantone book shop!

[HudsonDisplayServices]

Hi David, squeezee has it dead right. The Pantone (solid to process) swatch book OR the conversion in PS or AI (assuming default settings) - give you the percentages you need to get the colour you want on a web offset press, on a particular paper, with particular inks.

Those numbers will only be accurate in those circumstances. On any other output device/paper you'll need different numbers to get the colour you want.
(take a look at CMYK? Which CMYK ?! | Hudson to see that illustrated)

Here's the key point though - if your printer/ink/paper combination isn't accurately profiled - there is no way of getting an accurate screen to paper match. You're destined to always produce via the print/assess/tweak/repeat process... and that can be hideous. (especially if you're chasing a colour that isn't possible on your ink/media/machine combination - you can chase those for weeks and never hit them.)

Many designers "don't get" colour profiles. Weird when you think that you guys use them more than anyone else! You're using them all the time, in every element of your work. It crops up in discussion around CMYK most perhaps - just because there's so much bad information out there and printers who also "don't get it" - so you have the blind leading the blind. But you're using profiles in every website, in every browser, in every prog you use, and on every screen you look at. I'm guessing you have a number of browsers, take a look at Profile check - iPhone in different browsers, especially older ones. Notice how the very same page looks different on each? You can accurately control colour on websites in all browsers provided you understand ICC profiles and how the browsers use them - but if not different browsers could show your website elements as different colours. This explains how safari/explorer8/firefox, and the iPhone4 display things. iPhone4 and Colour Management | Hudson

Apologies for putting so many links in a post - but I saw the phrase "colour profiles doing strange things" and it rattled my cage. To "get your head around" colour profiles is simple, and will save you hours of time going forward. Here's a link that'll do the job for you! The Online Colour Management Training Program | Hudson about half way down that page is a link called "sample video". It's actually the whole of the first lesson of the IPA's Colour Management Fundamentals course, and it's free to view. It's 13 minutes long, and it will get your head around colour management. At 12minutes in, it answers the very question you posed at the top of this thread.

I'd be really interested to hear if that sample video gave you information that will be useful in your work, your feedback would be greatly appreciated.

Regards,
Craig

[djb]

I’m up to my ears in deadlines at the moment but will definitely watch the video and report back. Colour profiles baffle me so I guess it’s about time I got the hang of them!

[squeezee]

There is an idiots colour matching method :- print out a colour atlas and record the RGB/CMYK values, pick out the nearest colour and choose that in your DTP. It won't work for photos but those are usually colour tolerant. It works best for logo colours and spot colours. And can someone tell me why my browser underlines colour in red as a spelling mistake but not 'color' which is a mistake a three year old makes!

[spottypenguin]

Is your browser spell checker set to UK or US standards? if it's US the "color" is correct (in its terminology)