Banding/Color Breaks in Gradients in CS4 After Applying Printer Profiles?S

Question

Still pretty much new to working in Photoshop CS4 and this occurred during creating a painting with a graphics tablet rather than working on photos.  I'd obtained profiles to the printers/papers at a Giclee printer's shop and had applied them to this particular painting in CS4 when a gradient I had well established within the work going from approximately fire engine red to it's blued down shadow tone developed a tannish yellow break area between the bright red and the shadow tone immediately upon application of the profile.  I went ahead working on the piece figuring I probably had to pretty much redo all the coloration to a more intense level being that the application of the profile immediately dulled the picture waaaaay down presumably being that it's going on matte paper and it was during this stage that I discovered a good deal of banding of out-of-place colors throughout the overall color bar in the color selection side window (not sure of the correct term) and there were irregular, soft edged, swatches of out-of-place tones within the square gradient window.  Is this normal under these circumstances?.....Does one just work around this presuming it has to do with limitations of the printer/paper whose profiles have been applied or has something gone awry?  Thanks...

Answer 1

GTX56 wrote:
I'm wondering if I may have mistook some advice received here some time back that may have assumed I was working with photo images to be printed....Am I understanding correctly that, doing digital artwork from scratch in CS4 as opposed to modifying camera generated images, I should be working in CMYK rather than RGB?
In most cases, when dealing with photography, it’s much better to work in RGB. The conversion to CMYK should occur at the final output stage, whether it’s from InDesign, Illustrator, or Photoshop. That way if you are dealing with a faulty CMYK profile, you (hopefully) have the option of obtaining a better profile later on and simply re-outputting. Just make sure you soft proof in the correct CMYK space on a calibrated profiled display.
To do this using Proof Setup, make sure the rendering and black comp match what you will actually use for the final conversion. Then in the display options check “Simulate Paper Color”. If you have a good CMYK profile and an accurate display, this produces the best soft proof – it honors the file conversion that has not occured yet, then uses an Absolute Colorimetric intent to properly render paper white and black ink lab values (which are built into the CMYK profile). Absolute Colorimetric should not normally be used for file conversions but it should be used for proof conversions, and a display is a behind-the-scenes proof conversion.
This could possible affect the banding you see.
If you have elements that need to be precise CMYK numbers (good example as mentioned, 100 K text) it’s best to set up these things in another application such as InDesign. Then it’s a matter of placing the Photoshop RGB in the document, creating the black text in the document, and converting the RGB to CMYK when you export a PDF from InDesign.
Even if all you have is Photoshop, you can save a Photoshop PDF and retain editing capabilities. In this instance you can convert to CMYK in the PDF dialog. The PDF output portion of the file will be CMYK, and the native portion remains RGB. It can be a very confusing workflow without much room for error but it can work.
You can also wrap up all RGB content as a Smart Object, and convert the parent file to CMYK. There are rare instances where this is warranted, and you retain the source RGB. Also a dangerous workflow, but it’s an option nonetheless.
As mentioned 16 bit is best for source RGB, but it can slow things down a bit. If you choose to work in 8 bit, double check the gradient tool to make sure dither is on. And likewise if you have a need to convert to CMYK in Photoshop, make sure dither is enabled. (I don’t believe dither is an option with 16 bit).