Banding using illustrator gradients

[choco]

we have a Konica 6501 and we are having some issues when we print gradients created in Illustrator or ever Indesign. I tried different setting in the Fiery and i kind of improve but is still no good enough. If anyone has a feed back on this will be much appreciated. Have a nice weekend

 

[UberTech]

The quality of gradations is down to the accuracy of the 'Gamma offset adjustment' Check your POD Admin guide. Your tech should do this however.

 

[Massy]

We have the same issue with Xerox DC242. The tech said that there is nothing we can do about,it's just the limitation of the machine. Is this really true?

 

[Gregg]

The tried and true method to eliminate banding is to add noise to the gradient. So, if they are created in Illustrator or InDesign you would need to rasterize the gradient in order to add noise. Usually a small amount will do. I often apply 2% Mono Gaussian.

Not sure if this applies to the printers you are using, but if you are able to print in 16bit that may help as well.

 

[arossetti]

Change your screening settings. Default is normally 200 line - try a print at each setting your color serve gives you I'm sure you will find something that will work.

 

[Harrob]

I agree completely with Gregg in terms of adding noise. I see this problem across all vendors machines. If you even look at the file on screen you can easily see the steps in the gradient.

 

[LodAssoc]

A lot of Digital Machines will have problems with gradients. There are a couple of things that you can change in your file:

1.) Make sure your colors fall in the color gamit of the machine you are running.

2.) Add more steps into your gradient. Give it a bigger span to give more chance to transition from tone to tone.

3.) Add a small amount of noise (no more than +2 or 3). You should be able to do this on your RIP.

4.) Add Gaussian blur in your Illustrator file. Again, just a little bit.

5.) Use lighter colors

6.) Make your gradient in Photoshop, with a high DPI, and many steps.

7.) You may need a combination or any of these.

Hope this helps...

 

[Lennyr]

Many times banding is caused because not enough care was used in creating the gradient. First of all never set a gradient in InDesign, unless it's for a very small area. Indesign allows you only one color slider.
Gradients require very large mathematical calculations in the rip. The larger the size of the gradient the better chance of getting banding. The trick is to minimize the calculations that the rip has to make. If your gradient goes from white to black then you should put a 25% black slider at the quarter-way point; a 50% black slider at the half way point, and a 75% black slider at the three-quarter point. This breaks that one big calculation up into 4 smaller calculation and decreases the chances of banding.
Make sure that your 'raster effects setting' (in Illustrator) are set to at least 300 (I've seen many gradient problems caused by a 72dpi raster setting).
If you still get banding try 'expanding' (in Objects) the gradient (use a copy).
If all else fails save it as an PDFX1 pdf file. This converts the pdf to Acrobat 4. Acrobat 4 is not subtle when it comes to flattening objects, and can sometimes be the easiest method to deal with this problem.
Lenny R.

 

[EASYdoor]

These are interesting suggestions, but they are all software based which means you have to "maintain" two versions: one for digital, other for offset - for best quality and that can be very time consuming.

On our dc5000 with creo cxp50 you have "image noise" function and there you can set the "noise" but only for gradients - which improves the quality of the gradient. But unfortunately i cannot find such an option for our dc250 and cx250 rip

 

[Lennyr]

Banding

Banding

Adding noise is admitting defeat.
Lenny R.

 

[thom2c]

Banding and Adobe Illustrator

Banding and Adobe Illustrator

If you need to add noise you can do so in the 'output' settings in Fiery. But as others have said just a little bit. It is better to break the gradient into quarters in Illustrator such that the RIP processes the file in small sections though it may add time to the ripping.

 

[EASYdoor]

Thank god i was reading this forum, just yesterday i've used this method learned on the forum into practice, here's the situation: - customer send me an corel file with lot's of circle gradients - but as a texture fill! not as a gradient - if it were a gradient you can improve the quality by setting up the seps of gradients to 999 and in print options also to the max which is 2000 i think....we'll in this case i've set the texture resolution to 1200 dpi, converted to bitmap also to 1200 dpi and then exported to pdf - edited the image in photoshop (because i don't like photopaint ) pimped the colors a little bit, then added 2% of noise and some blur. The ripped file was over 500 mb, because it was imposed onto SRA3 format, but the result was excellent! on dc250 with creo cx250 or dc5000 with cxp50....i was really astonished by the quality that i've produced on the digital press,...i guess that the logic behind gradients on RIP's is very different and perhaps to complex to produce a quality result in decent time...