Hudson's Edge - Colour Space

Getting Your Designs Noticed: How to prepare your artwork so that your prints will outshine your competitors’ – every job, every time.

Hudson's Edge: In a busy marketplace you need every edge you can get over your competition. Hudsons can provide that edge. Importantly, it won't take any effort, and will cost nothing. All you need is that fraction more knowledge than the rest. Which is where we come in. We’re here to make you look good.

Craig Hudson, one of our IPA Qualified Colour Management Masters, demonstrates why breaking from the usual conventions will get your artwork noticed in a crowded market. Hudson’s Knowledge Base contains several theoretical discussions of colour spaces. This article demonstrates the difference when it comes to actual print output.

Most wide format printers request that you send your artwork to them in CMYK. In doing so they limit your colour and deaden your print. By breaking from the norm, you can stand out. This article shows you the difference that can be achieved.  

Consider this artwork file, Mike Adam's trusty evaluation image.

You don't need to understand colour spaces to see this difference. The top image is in the AdobeRGB colour space. A large RGB space that contains more colours than most monitors can display and more colours than CMYK printers can print. If we follow traditional thinking, before sending your artwork to a printer you're going to convert to CMYK. The bottom image is the image converted to USWebCoatedSWOPv2 (SWOP is discussed HERE - it is the default CMYK colour space in AdobeCS. If you change a document colour mode from RGB to CMYK, or create a new CMYK document, unless you specify otherwise, you'll be in SWOP)

Now USWebCoatedSWOPv2 represents the output of a SWOP certified offset press, onto a particular paper. When you send me that file to print, what you're really doing is asking me to match the output of a SWOP certified offset press. Now that's fine if that's what you need. Maybe the wide format print you want me to do has to match the cover of your catalog, run on a SWOP certified machine. In those circumstances, you've created the perfect file.

BUT - What if you don't need it to match a catalog? What if the wide format print is all you need? You just want the best print you can get of that punchy original file. Well first of all, lets read the two images above in more detail. Is the SWOP print so bad? It's bright, it's punchy. Isn't it? Look again. Look firstly at the solid colour bar in the bottom right of each. Then look at the colour map. Wow, the SWOP version is so dull! Now look at the photo of the girl, but look at the neon blue background in the top right corner. Look at the extreme colours in the hair and makeup. It's not easy to compare when your eye jumps between the two. Try this chopped up image instead.

Look at the green eye makeup and the strong blue hair - vivid like a parrots feathers in the AdobeRGB, very dull in the SWOP version. Look at the bright pink and green hair... lacking energy in the SWOP version.

Now remember, the SWOP version is how the AdobeRGB image would look printed on a SWOP certified litho press. But if you do the CMYK conversion and send me that, that's all I can print. I can't convert it back and regain those colours. Of course, you could send me the original AdobeRGB file. If you want it to match SWOP you can ask me to do that. but if you want as close to the original as my machines can manage, then I can do that for you too.

So why do people ask for CMYK files? So that the designer gets no surprises, the limitations of the CMYK process being clearly visible before ink hits paper? Well yes, that makes good sense if you're outputting on a SWOP certified press. but what if you're outputting on a printer that has different limitations to SWOP? If the digital printer can print more colours than SWOP, it can do a better job of printing the original AdobeRGB file than a SWOP printer can. BUT you've already limited your file to the colours available to the SWOP printer. The rest of the digital printer's potential for colour is wasted.

But it's never mattered before! Is it a big deal? Lets take a look.

This image shows how the two files print on a Mimaki JV3 on LD3810 white vinyl from LG. The bottom image is exactly what your file asked for. Because it didn't ask for a colour the printer couldn't manage. So if you follow the conventional "submit in CMYK" path you get an accurate print, and it's nice enough. But look closely at the top image. This is what you'd get if you sent the AdobeRGB image to us. Follow the same process as earlier. The colour bar in the bottom right... It's more subdued now than it was when we looked at the original - the JV3 can't hit all the colours in the AdobeRGB space, BUT it can do better than SWOP. Look at the colour chart, the biggest noticeable difference is in the dark vibrant blues.. now look to the top right corner of the photo... the background blue. The JV3 can get far closer to the original than the SWOP image is asking for.

Lets look at those cutout bits again.

You can see that the Mimaki doesn't fare that much better than SWOP in the red and pinks, but look at the deep blues and the greens to see the obvious differences. That green flash coming away from the eye is a great example.

What I've shown here is that sending your artwork in CMYK (SWOP), whether created in CMYK to start with, or converted before sending to us, limits your colour to well within the capabilities of our machines. 

Submitting CMYK (SWOP) artwork is a safe way to work. Most people work that way. But the thing with conventional wisdom is that it's conventional! Everyone is doing it!

Now think about this. Machine manufacturers advertise their "most vibrant ink set yet", and printers like me shout about our punchy colour. BUT we also shout about how accurate our colour is. If your artwork asks for punchy colour we'll give you it, but what happens if you submit SWOP artwork? That new inkset is absolutely pointless - the artwork file can't ask for any colours beyond the SWOP colour gamut! So we've got a huge colour range, and your file is only asking us to use that same small section of it that everyone has used for years. Printing a SWOP image on a machine with a huge colour range is like getting into a Ferrari and driving down the racetrack at 20mph. The potential is yours to use... but you still have to put your foot down! Send us files that ask for more than SWOP - send us files in big RGB colour space - and your prints will stand out next to anything produced from SWOP! Build your artwork in AdobeRGB - and you can take your designs into places that those working in the conventional "submit in CMYK" way simply cannot ask their printer to go. 

The difference discussed here is small, but powerful, and it will get your work noticed. That small difference is the difference between an ok print that your client will pay for, and a great print that your client will thank you for.   

Of course, the printer you use has to know what they're about. It's a little frightening to realise that many don't. Hudson Display Services Ltd define ourselves as "expert partners". This is us offering you that expertise and partnership. Other printers want you to submit safe CMYK artwork, but for whose benefit? If you submit safe CMYK artwork to us you'll get a great print, exactly what your file asks for. But if you're ready to ask for more, we're ready to give it to you!

At the top I promised no effort, and no cost to implement this. All it involves is changing your default colour settings in Adobe CS. Once done, it's done. Just design away and explore the extra colours you can now achieve! 

If you'd like help doing this, a .csf file to import to setup CS for you, or to just discuss this with our colour experts, give Craig a call on 01702 232500.

We're here to make you look good. 


This document has discussed CMYK as SWOP. The author recognises that there are many larger CMYK colour spaces than SWOP. The discussion is in the context of real world print production and our experience is that when artwork is submitted in CMYK, it's nearly always in SWOP. Whether by design or accident doesn't affect the argument.

There are of course bigger colour gamuts than Adobe98 - and many have argued the case for working in a space such as ProPhoto. To successfully use such a space needs a thorough understanding of colour theory, and goes beyond what we're trying to achieve here.