How do I create a CMYK rendering for Print?

[Jimdeasy]

I need to create a poster featuring some of my renderings from Bunkspeed. Although, I cannot see how to create a CMYK image. All my renderings are RGB and become very dull upon conversion to CMYK in Photoshop, or Indesign. As I cannot send RGB files to my printer, I need advice on how to create the file in RGB directly from Bunkspeed.

[david.randle]

You need to load a better color profile in Photoshop that can do a better conversion of your RGB image to CMYK. Also, if you are seeing a big difference, it is likely because a lot of the colors in your image are out of gammut for the particular CMYK profile you are using.

This world is a little bit our of my personal realm so i would appreciate other advice if anyone else can chime in.

Thanks

[andy]

it is worth noting that just like a digital camera, you can't render in cmyk, and for the same reason. One is a value of light, the other is a value of ink. If you calibrate your printer these days, you actually get better results printing from an RGB image. Unless your calibrating the printer itself outside of a computer with a densitometer, then CMYK doesn't really mean much. You'll still have to use a color profile to match the printer's current status. Just having a representation of CMYK on your monitor isn't even really accurate because it's light.

As Dave mentioned, your colors May be out of gammut for CMYK, or out of gammut for your specific printer. Each one is different. Just because you give it a value doesn't mean it can print it. The same goes for your monitor. If your monitor isn't calibrated, you can pretty much ignore any color it displays. It won't print out looking like what you see on your monitor.

Also, even if you have good profiles, the CMYK/RGB conversion doesn't play nice. To see an example, create an image in RGB 0,0,0. That's black right? Now convert to CMYK. What color is it now? Now convert back to RGB. That's not black. It's a really dark brown, and it's terrible. Anyway, you'll get better print results in letting a calibrated print driver convert the color than you will just converting it to CMYK. Printing in CMYK ignores your color calibration because it thinks you did that already. Basically, unless you're sending your prints to someone who calibrates their printers with densitometers, and Not spectrophotometers, don't use CMYK. And if you didn't calibrate your monitor, then there's no use in even trying. You'll see red, and your print comes out purple.

[Alona22]

As Dave mentioned, your colors May be out of gammut for CMYK, or out of gammut for your specific printer. Each one is different. Just because you give it a value doesn't mean it can print it

[BrianHillner]

Great responses, gents.

I would add a very "stone-age" response. I am a photographer on the side, and print TONS of images through a variety of printers and print-houses. If you have the option, and aren't printing to a company you have a Groupon for (haha), here is my suggestion:

Reduce the overall size of your render, poster, print, image, etc to a preview sample size (ie: 3" x 4") that any print-house will print for free. This way you can have a direct comparison to what it looks like on your screen and what the final print will look like fro the exact printer you will use. Although archaic, this process will work 100% of the time, allowing for tangible adjustments to the image. Repeat as necessary. If you are printing on a wide plotter, you could even line up several color profile versions of the same image for the print-house to test print. Once you find the best representation, save any adjustments made to the image as an "Action" in PSD with the exact printer name in the title, and then play this action on any render you indend on printing on that same printer for future use.