PDA

View Full Version : CMYK Info


CypherXero
03-29-2005, 12:39 AM
I need to learn about CMYK, how it's used, how to properly use it with Photoshop CS, and how to properly print images with CMYK for large format (professional) printers. I'm very good with Photoshop (http://cypherxero.deviantart.com), but I have no experience with CMYK, and printing documents with professional printers using this color space. Any information and/or links to tutorials would greatly be appricated. I guess I'm just used to working in the RGB color space, making images only for display devices, not printing.

dudders
03-29-2005, 10:32 PM
hmm not much to really say, other than you really need to calibrate your monitor correctly for accurate output.

Here are some noters:


CMYK colours can appear a lot duller than the screen presents. Its worth investing in a good printer to proof your own work before sending it away.
When using large expanses of black make sure you have whats called a shiner in there. This is a mixture of inks rather than straight black which can appear flat and not black at all. This is useful especially for large black text. In photoshop you sometimes have to trust the values for this because sometimes it doesnt look right. I use a 60% Cyan with 100% black for a shiner, but it depends whether you want a warm or a cool black.
Keep in mind that printers can sometimes go off registration, or the different plates they use for the colours c,m,y and black can go out of line slightly. For small stuff like 9 point text or below try and use only one plate of colour otherwise you can get nastly blurry text.
Orange flat colours are hard to recreate with cmyk, so is green. Orange usually comes out kind of browny.
You can use special colours which come from a pantone reference book for vibrant flat colours, you should invest in one of these but they are expensive.
You can also use a spot UV varnish, this gives certain areas a shiney, varnish look. You specify where this goes as you would ink. So in that anti-ripper pic you could spot UV the red arrows or the red magnifying glass thing to help bring it forward.
Think about paper finishes matt, gloss and silk. And also you can buy in special papers from people like fedrigoni that have pearlescent finishes, there're so many to choose.

OamadeusO
03-30-2005, 12:14 PM
I do a lot of packaging work so I have to use CMYK colour values a lot.
As said above a good printer for pre-proofing your work before you send to the printers is a must. I use an epson photo 950 for my A4 stuff an a 2100 for my A3/Super A3 work.

I also find that oranges are a bit dull sometimes. One of the licenses I work with is "Action Man" that use a spot printed orange for their logo. Otherwise its brown. This puts the cost up because it's another screen.

The tip about putting a shiner on black is a new one on me and I will be sure to use it myself.

The last point is I have noticed that some PCs have problems reading CMYK documents.
Years ago I was trying to send a customer a JPG and he kept sayign he cant read it until I changed it to RGB. On a side note some picture viewers seem to have problems reading jpgs over 300dpi

dudders
03-31-2005, 03:58 PM
The last point is I have noticed that some PCs have problems reading CMYK documents.
Years ago I was trying to send a customer a JPG and he kept sayign he cant read it until I changed it to RGB. On a side note some picture viewers seem to have problems reading jpgs over 300dpi

Yeah this happens usually when the other person is opening jpegs with their web browser, which before XP used to be the default thing with windows, and they dont recognise CMYK.

ddaniels
04-01-2005, 01:34 AM
I have been doing pre-press for years now and doing color conversions for artist just like you from RGB to CMYK my first response would be to start working in a CMYK color space (like a swop working space) if you know its going to be a printed piece. That however isnt always know of course. Like everything else you need to get some experience coverting from the two. Everyone things its just a click away to convert but you need to understand the color setting in Photoshop and also need a good understanding of GCR and UCR. You also need to know how its going to be printed ever printer has a different color space. Thats why profiling has come into being and implimented in photoshop. You can get or create a profile from you printer and work in that so that you know what your going to get. Guess i have rambled on enough. Would glady answer any questions you have. The main thing is like everything else practice practice and dont be afraid to ask more questions.

CGTalk Moderation
04-01-2005, 01:34 AM
This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.