Banding

[Jennifer_Johnson@adobeforums.com]

Help! I have a horrible time with gradients/banding.

I have a 8.75" gradient. It's four color now, but before it was converted, it was spot (Pantone 1235 100% to Pantone 1235 5%), linear, angle 93.29.

This is the first time I've had an issue with banding. Is the blend stretched too far? I don't have control over the print settings (file supplied for client to take to print shop).

Now the print shop has indicated it will band. Can I increase the color percentage at the low end (then convert it to CMYK again)? Or is the length too much to support it?

[Philip_Peterson@adobeforums.com]

Starting on page 363 of the illustrator 10 manual (you didn't say which version you are using) it covers this topic.

[Jennifer_Johnson@adobeforums.com]

Hi,

It doesn't answer it completely & neither does the online help, that's why I posted here.

If I have a linear gradient at approximately 90 degrees, and the w/h of the object is 8.77"/0.361", the length you can "stretch" it according to the formula is approximately 6" (approx. 75% change in color). BUT if it's at 90 degrees, is the height the "stretch", or is the length still the determining factor regardless of the orientation of the gradient.

Also, if I used the gradient tool to manipulate the placement, how do I determine the "start and end" of the gradient? I just assumed it was the length of the object.

As I stated, I've never had this problem before, so I'm unsure whether it's something I've done with the file or whether it's something on the print shop's end.

Sorry for the basic question, but I was hoping someone could help clarify what's covered in the User Guide. ??

[John_Kallios@adobeforums.com]

Yes, it does answer it completely based upon postscript 2 devices which is most likely the issue you are facing now.

A postscript 2 device yields 256 gray levels while a postscript 3 yields 4096 gray levels.

Confirm the ps level of this printer and if it is 2, you will need to create the gradient in Photoshop and add noise or dither it.

If you are talking about blends and not gradients, blend gray levels are reduced to the ammount of steps in the blend.

[Jennifer_Johnson@adobeforums.com]

OK, that's the info I needed. I never use Photoshop (just do logos, so I use Illustrator exclusively & don't use gradients that often), so I'll have to figure something out if it's a ps2 device. :-)

[Jacob_Bugge@adobeforums.com]

Jennifer,

The length must be in the direction of the gradient.

Pantone 1235 is quite pale though. I have not tried to calculate it, but maybe it is hard to stretch it that far, maybe easier if you keep it in Pantone.

Have you tried adding colour squares? Just a thought.

[Jennifer_Johnson@adobeforums.com]

Hi Jacob,

Thanks for the info. That would make the length less than 1" then? So theoretically it shouldn't band. :-(

I'm not sure what you mean by "adding colour squares"...

I'm going to check into the ps2 thing today and see if that's the issue. It could very well be.

Thanks -J

[Jacob_Bugge@adobeforums.com]

Jennifer,

Your second post seems to indicate that the gradient is from top to bottom, only 0,361" which is far below the 6" maximum blend length, whereas the 8,77" would be higher. Is that true?