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In illustrator did you check I two places the Document Raster Effects Settings and in the Document Set Up the Transparency Settings are they high enough.

In CS 4 I do not see this and do not recall if it happens in CS 3.

I wonder if the "View" setting is an issue ( i.e., InDesign's low vs. high quality ), too. And, maybe "Anti-Aliasing" is set to "OFF"? Document and raster res should be 2540dpi/300ppi minimum, but not sure that could be affecting the view. How does the file print? Is the banding showing up in output ( to a fairly reasonable Postscript 3 RIP or high quality "Press" PDF )?

One thing that will cause banding is jpg compression, even though you have got good resolution. This happens both in Photoshop and Acrobat if you use jpg somewhere along the line. For seamless gradients use another either LZW tiff or no compression. Your files will be considerably heavier, but that's what you pay for smooth gradients.

John,

Where do you get the idea that Document Raster Effects settings should match a "document resolution" of 5080 or 2540?

> "300" is way too low ( if you are referring to document resolution, not image resolution )

Document Raster Effects is a raster image resolution setting: it's the resolution of the raster images that are created by Illustrator's raster effect features. Specifying a raster resolution that is 1:1 with an imagesetter's dpi is ridiculous.

Further, where exactly is it that you "usually" set a "document resolution" in Illustrator CS3? The document resolution setting in earlier versions was simply the flatness setting, and defaulted to "800 dpi" (which is a flatness of 3, assuming a 2400 dpi imaging device). That setting is no longer even present in Illustrator, since (as I recall) AI 10. Flatness had nothing to do with grad fills; it affects curve accuracy.

You guys are talking about a problem with banding--the OP implying that he has been investigating the problem for some time--responders even offering suggestions to "fix" it. Yet no one in this thread has yet stated any of the specifics that are necessary to even talk about banding:

Where is the problematic banding occurring? Paddy Rogers does not even say whether he is talking about banding on screen or in output.

Assuming the banding is in printed output, what kind of device is it? If it's an imagesetter, is it using PostScript level 3?

What are the CMYK color values between stops of the of the page-size grad fill?

What is the size of the page (distance the grad spans)?

What is the halftone ruling being used?

These suggested "fixes" are myths:

Rasterizing the artwork
This is nonsense. It doesn't matter if the color values across a uniform grad are from vector commands or actual colors of pixel bands. Raster grads yield banded results just as easily as vector grads do. Banding is a function of the dot size and halftone ruling of a printing device. Rasterizing doesn't magically increase the resolution of a printing device.

Setting Raster Effects Resolution to a higher value
This has nothing to do with grad fills in Illustrator. A grad fill is not a raster effect.

Transparency Flattener Settings
Again, has nothing to do with banding in grad fills. A low setting may result in pixelation, not banding.

Antialiasing
Has nothing to do with banding in graduated fills.

Paddy, you claim that you are experiencing increased banding in both Photoshop CS3 and Illustrator CS3, as compared to the CS versions of those apps. Have you actually compared the same files being sent to the same printing device? If so, provide the specifics of a page-size grad that reliably produces the problematic banding. Be sure to state exactly what device you are printing to.

JET

any other words on a solution to this topic?

If we create a white/gray radial gradient in illustrator, save it as a pdf, open it in flexi sign software to send to a Roland Wide Format Injet Printer... we are getting major banding. Plus, in illustrator on screen I can see major banding if I look closely.

What should be our trouble shooting steps to look at if all of what James states there is correct? James? Anyone?

Thanks!

Wow! I'm a month late on returning to this thread, and I hate having to concur with JET 8^P but this is patently incorrect. Document Raster Effects Resolution should never be the imagesetter resolution.

If you follow the same logic then any raster document you create in Photoshop should also be imagesetter resolution. How about a process color Business Card file? 172MB for 8-Bit color (344MB for 16-Bit for due diligence).

Document Raster Res should be 300 dpi maximum up to 175 lpi output. Industry standard is 400dpi for 200 lpi though 300 will suffice in most instances as well.

People have to be very careful about the answers they give in public forums like this.

Stupid double post on a forum hang! 8^(

Not necessary jean p I have an old version of Illustrator (CS) loaded on an old G3 and that can display perfect gradients and lines
but CS 3 and 4 do not on a Intel Mac. But the same screen

I was wondering what kind of supercomputer you were running, John! We had someone accidentally create and distribute a series of templates with DocRasterRes at 2540 dpi and it was making our new Intel Macs craaaaawwwwlllllll It's all good!

This happens both in Photoshop and Acrobat if you use jpg somewhere along the line.