Problem with brushes and saturation

[alexm12034253]

Hi,

I've got a trouble in drawing with a brush after performing a changing in saturation/hue of a layer. After performing that, the brush doesn't behave as it should, as it becomes whiter and you need lots of strokes to get the color. This problem gets worse when trying to draw with a 50% transparent brush, then every single color gets whiter and it seems to have some white halo, over the layer treated with hue and saturation. Does anyone knows what is happening, and how I could solve that?

I post a picture of the weird effect. Thank you all!

[c.pfaffenbichler]

The screenshot is too small for me to be sure if the image is CMYK – is it?

If so: Why?

[alexm12034253]

Hi, Image is in CMYK. It should be in that colour mode as it will be printed. Could it be aproblem with that?

[D Fosse]

Standard procedure is to work in RGB and save that as the master file. Then convert a copy to the CMYK profile that applies to the actual press conditions (you won't know which until you ask the printer).

This avoids a bunch of potential problems, like exceeding maximum ink coverage resulting in smearing and drying problems. It also lets you repurpose the file easily for different press conditions.

[c.pfaffenbichler]

Image is in CMYK. It should be in that colour mode as it will be printed.

Not with this kind of image.

Think about what you are doing: Suppose you have a background of 100/0/0/0 and paint on it with 0/100/0/0.

What is the exact middle of the two is 50/50/0/0.

So by painting in a CMYK image you cause yourself unnecessary problems. 

[c.pfaffenbichler]

I guess with black and a primary the effect is even more noticeable.

And for mixed colors the GCR settings of the Color Space can have a significant influence.

Even though by painting or otherwise editing a CMYK image one may mess that up anyway.

[alexm12034253]

Thank you all so much!!!! Problem solved! Just using a RGB image it works properly! Thank you again!

Explanations were fantastic! You rule guys!!! Thank you all!

[davescm]

One thing to add to the above.

If you are printing your output on an inkjet - do not convert to CMYK. Inkjet print drivers are designed to work with RGB data.

Only if you are sending to a printer , might you convert to CMYK, and then, as stated by D.Fosse earlier, only to the CMYK profile specified by the printer, if he/she can't tell you - use another printer!

Dave

[c.pfaffenbichler]

Yet another thing: Certain images can warrant working in CMYK right from the start, for example if a graphic or drawing features thin black lines that one wants to print as pure black (to avoid registration issues).

But photographic and painterly images should be edited in their original RGB as much as possible.

Separating the images in Photoshop may offer the advantage of looking the result over In more detail (and noticing banding issues for example early on) but if the images are being places in Illustrator- or Indesign-documents one can also place the profiled RGB images and separate on output when exporting the pdf.