Not wholly OT - I got the CMYK rookie BLUES

PeterWright wrote on 2/4/2008, 1:56 AM
I've been asked to supply CMYK versions of a DVD label and sleeve for a mass Replication DVD project.
I've never dabbled in CMYK before, so I'm a bit GREEN ..... I used Paint Shop Pro to split an RGB graphic, and it produced four files. named Cyan1, Magenta1, Yellow1 and Black1.

These all look like GREYscale images. Is this normal? - I thought it strange, but then I realised it might be that the degrees of grayscale tell a printer how much of C, M, Y and K to print.

I hope my attempts to be punny haven't BROWNed you off, and hope that, having RED this post, someone can put me in the PINK.


farss wrote on 2/4/2008, 2:04 AM
I think what you have are separations, so yeah each image is just greyscale for that ink. To be honest you might be better off giving the task to someone whose done it before, I think the process is part of "prepress" but not certain, I spent a few weeks working around printing presses, long enough to realise it's a messy business best left to experts.

Kennymusicman wrote on 2/4/2008, 3:49 AM
Yes- your 4 CMYK files are for each of the plates in the printing. With photoshop, and I would have thought for PSP, you should be able to save your file as CMYK - a single picture format file. This is what you want. The idea is that if you work to CMYK with your imagery, then it will be printed out much more like you expect - as RGB does not equal CMYK.

After that you start getting into monitor calibration and much more. At this point is becomes a bit of a GREY area as the printer will have a different profile to your monitor and things don't quite come out as expected.

Allow yourself plenty of time to print of dummy copies that you can then adapt to get your imagery look good,
PeterWright wrote on 2/4/2008, 4:40 AM
Thanks KennyM and Bob I'm keen to learn, and I am learning, but ....

I originally expected to be able to save as something which "was" CMYK, but the only Save as choices are the "usual" formats, bmp, jpg, tif, png, psd etc, so I therefore expected to be able to change the properties somewhere from RGB to CMYK .

Now, whilst the PSP Help files talk about configuring the preferences to determine how PSP handles the conversion from RGB to CMYK, I've searched and searched but cannot find anywhere how to actually DO the conversion - all I've found is Colours / Split Channel / Split to CMYK, and that's what I did to produce the four greyscale files.

Maybe if you could describe the steps Photoshop would go through to do this I can discover the equivalent in PSP ... or can I just give the four greyscale files to a printer and relax? (optimism's a wonderful thing!)

farss wrote on 2/4/2008, 4:50 AM
In PS you need to change the Image>Mode, that's the clue.
You can then save in a number of formats that support CMYK.

You've probably been working in RGB which is different to CMYK, I get a few CMYK images sent to me and there's not much you can do with them so I change the mode to RGB.

If you really want to get in a tangle wait until you have to deal with Pantone colours.

Kennymusicman wrote on 2/4/2008, 6:07 AM
Peter - what version of PSP are you using? - I have an older copy round here somewhere that I can look into..

AS Bob says - PS makes it easy by a simple menu & click.
RNLVideo wrote on 2/4/2008, 6:47 AM
As Bob said, Image > Mode in Photoshop. I don't have PSP, so not sure what the equivilent is. But - try searching for "color space" or "color gamut" in PSP. This may lead you to the how-to.

bStro wrote on 2/4/2008, 7:53 AM
I thought it strange, but then I realised it might be that the degrees of grayscale tell a printer how much of C, M, Y and K to print.

For the record, this is how RGB works, too. If you split your image into RGB channels, you'd get three greyscale images -- showing what levels of red, green, and blue make up the image.

As for Paint Shop Pro, it can't change your image's color model. This from PSP9's help file:

"Although you cannot create images in Paint Shop Pro using the CMYK model, you can produce color separations that can be printed on CMYK printers. There are two ways to do this: You can split the images into CMYK channels or you can print color separation pages."

(Emphasis mine.)

You could find someone with Photoshop to change the mode, or I suspect there are freebie tools available online that would do it. Question is, would the label look right since it wasn't actually created in that mode?

Kennymusicman wrote on 2/4/2008, 8:01 AM
Rob - you literally just beat me to quoting the PSP9 help file!
Coursedesign wrote on 2/4/2008, 10:41 AM
It doesn't matter what mode it was created in, but for starters CMYK can't print nearly the number of colors RGB can. The gamut is smaller, and it also depends on the paper you're printing on. Photoshop has built-in settings for a number of different print CMYK standard printing methods, but then there are a number of other reasons why people spend years getting proficient in this.

If you care about the quality, you really should pass your RGB file on to somebody who can communicate with the printshop and give them a "calibrated" CMYK file that will give a printed end result that looks like you expect.

Not as easy as you might think, and it takes some skill to know which colors simply cannot be printed in 4-Color process, so they need spot color (special ink run with the color usually specified from a Pantone patch book), or Hexachrome (a 6-Color Process), or special papers.
PeterWright wrote on 2/4/2008, 3:24 PM
Hey, thanks for all the help - the only reason I got into this is because the DVD replication house said to "create in CMYK preferably", but since I already have perfectly good 300 dpi RGB graphics for label and sleeve, I think I'll pass them over and they can do what they like with them.

I have already burned and printed 50 DVDs, but now the client wants another thousand to send to each primary school in the State. (WA).

Thanks again all - this forum sure is an education.
farss wrote on 2/4/2008, 7:34 PM
What's probably not a bad idea is to give them a copy of what you've printed. Things should come out so close you'll not be concerned but having a physical copy of what it's roughly meant to look like as a reference wouldn't hurt.

PeterWright wrote on 2/4/2008, 8:00 PM
Good idea Bob - I also want to make sure they include an "Extras" folder from my prepare, so giving them a burned/printed copy will serve both purposes.