Strange cuts when flattening transparency

[Viktoria24203226e6hj]

Hi All,

how can I avoid these cuts when flattening transparency in illustrator?
I'm preparing artowork for print. This specific banner is a real size so they won't enlarge it but I have gotten feedback before that these lines appear on the print.

Previously they dindn't appear so I thought its a glitch in the pdf viewer
I think they come from these shapes that illustrator cuts the shadows and shapes into

What am I doing wrong?
I have different layers a tif background, some opacity gradients on top of that and other solid shapes with drop shadow.
Is there another way of expanding these and flattening than selecting them all and flatten image and keep transparency?
If I do each layer one by one then the visuals change a lot the images become dull and shadows change in appearance.

Thanks for the help in advance!

[Monika Gause · Accepted solution]

You could put the text on its own layer and then select everything below and apply the effect "Rasterize" with sufficient resolution.

[Ton Frederiks · Accepted solution]

Do you really need to flatten it? Modern RIPs can use the the Adobe PDF Print Engine, that can handle transparency very well. Flattening before sending it to print is not a good idea, it will cut up your artwork to get rid of the transparency and can result in tiny light anti-aliased lines around these regions.

[Ton Frederiks]

As an alternative you can rasterize the artwork that contains transparency . You can do this as an Effect to keep it editable.

[Viktoria24203226e6hj]

Well, I don't know if I have to. sometimes artwork goes to different printing company and its last minute send out so not sure we have time testing how shadows and transparencies are being handled by them.

[Kurt Gold · Accepted solution]

As Ton already indicated: Advanced print providers have been able to process unflattened PDF/X-4 files for many years (decades) without considerable issues.

Isn't that usual in your environment?

[Viktoria24203226e6hj]

Thank you we will try that from now on!