gradient banding exporting to pdf

[Flaz]

Hi, exporting to .pdf i'm getting banding gradient on vector shape like sample (print/press ready cmyk/8). Any way to get smooth gradient?  :)

[Dave Harris]

Affinity can export smooth native gradients, so I guess this one got rasterised. There are several reasons that can happen, such as using filter effects or complex transparency. I can't say much more without seeing the Affinity drawing.

[Flaz]

Thanks Dave,

no filter effects or transparency. Only gradient on shape and export to pdf. Zooming on vector shape I can see banding so I think gradient is rasterised for some reason.

[MattP]

Would you be able to post the .afdesign file here so we can look at it? We're currently unsure whether Affinity Designer is exporting this as a gradient and the viewer is showing it as banded, or whether the gradient was rasterised and that is the error? Any simple file showing this problem would really help, thanks :)

[Flaz]

Thanks MattP,

I'll send you a PM with file. Looks ok in Affinity Designer, bad when I convert to pdf.

[MattP]

I've replied to Flaz about this, but wanted to post the answer on the forum for anyone else that stumbles on this thread in future...

 

The problem is simply that the PDF created has correctly used the PDF gradient attribute, but that the software used to preview the PDF file doesn’t attempt to dither its gradients so you can see banding.

 

Affinity Designer is applying a dithering algorithm to all gradients by default in order to remove any obvious banding and try to improve the image quality. This takes time to do, so we allow for it to be turned off in Preferences->Performance->Dither Gradients. If you turn this off, you should see the same banding you’ll be seeing in the PDF viewer application you’re using. The banding is caused because there aren’t enough discrete colour steps between the source and destination colours in the gradient, so each discrete step is effectively used a number of times over the length of the gradient, causing an apparent stepping (banding) to be visible.

 

Dithering is the answer, but your viewer needs to have implemented this. Alternatively, if you just want it to look the same as in Designer, then your only option is to rasterise the shape which will turn it into a bitmap within Designer (Layer->Rasterise… menu item) so it will look the same in whatever viewer you choose. You can clip it to the shape if you want to make sure it still has a crisp edge at all zoom levels. This is obviously bad in terms of file size though.

 

Thanks,

Matt

[Flaz]

Thanks Matt,

turning on "dither gradients" I was confused by what I saw in the program and what is exported. Well, great support for great software.

[wemu]

Hi everyone!

 

Sry to open this thread up again, but I experience the same banding on my pdf exports. 

 

Now, I followed the steps as described by Matt. Turning dithering on helps to get rid of the banding in AD. However, when I export to PDF (usually PDF/X versions, e.g. 1a or 4), I still see the banding. Also when I rasterize the respective layer, I still see the banding in the exported pdf. 

 

I used OS X preview, as well as Adobe Reader for viewing the resulting pdf. Both show the same behavior, i.e. the banding. 

 

If I export from the same AD file to JPEG, I get a smooth gradient. 

 

Am I missing something? Any ideas?

 

Thank you, I appreciate the help!