Visual Artefacts when Publishing PDFs

[thesleepofreason]

When publishing PDFs I get visual artefacts in fills of intersecting elements. What I expect to be a continuous fill gets segmentet causing tears.

The effect is admittedly small but still noticeable even at normal zoom levels - especially for solid fills and thus makes digital drawings look sloppy.

Is there a way to avoid this when publishing? I does not occur when printing the layout using Adobe PDF so technically, it should be possible.

[thesleepofreason · Accepted solution]

To sum up:

These issues seem to ultimately be caused by the fact that AC splits fills into segments when publishing or printing to PDF which present issues related to anti-aliasing when the PDF reader renders solid fills with shared boundaries. In addition publisher creates a cliping mask for vectorial/symbol fills which causes the lines to be clipped and incorrectly displayed in PDFs.

@Minh Nguyen  It would be interesting to hear GSs thoughts on this. I guess that it is a rather tricky thing to get right.

These are the fixes I've found to work. 

For opaque solid fills - go through the render settings of the PDF reader. For Adobe turning off 'Smooth line art' seem to fix it but at the cost of increased aliasing. 

For transparent solid fills. Reprint the PDF with flattened transparency, eg. using Adobe PDF as printer.

For vectorial/symbol fills. Print to PDF instead of publishing or edit the PDF to remove the clipping mask.

[Minh Nguyen]

Hello,

Thank you very much for sharing your thoughts and experience with this issue!

I'm wondering when you print out the PDF to paper, will it be visible on the printed sheet?

As far as I know, indeed this happens due to PDF Reader's algorithm. At certain zoom, these artifacts maybe visible or maybe not, but from our experience, the issue won't show up on the prints. Could you please confirm it?

Best regards,

Minh

[thesleepofreason]

Yes, most cases print to paper without reproducing the artefacts but I guess that ultimately depends on the printer setup just as with monitors. 

But the question is - should we have to live with these issues for PDF drawings? A format that is widely used for presentations where we actually care about more than informative content of the drawing. A format which, being vector, encourages the use of zoom. Should I really have to choose between jagged lines or fill artefacts (given that the one viewing it even knows how to control that)? Should I really have to go though post-publish processes to get a clean presentation of a simple nature?

I understand that the implementation of a solution probably is harder than its conception but: the ability to merge identical fills of intersecting objects would solve all three issues; the ability to flatten the transparency of fills would solve the shadow issue (but turning it into the solid fill issue) ; and the ability to publish vectoral/symbol fills only as lines would solve that issue. 

[Minh Nguyen · Accepted solution]

Hello,

Thank you for the feedback, I totally understand the struggle caused by this issue. It also happened to me a few times. We had an existing about this (IDEA-3623), I already added your comment to this one. Hopefully, our Product Management team will consider adopting it in the near future.

Thank you once again for the detailed feedback, we really appreciate it!

Let me know if you have any further questions!

Best regards,

Minh

[Burcu Meral]

Thank you so much for the answer. But turning off 'Smooth line art' increases aliasing just as you said. Is there no other solutions to fix the problem? 

[thesleepofreason]

@Burcu Meral I share the frustration from not being able to produce high quality presentation material from the standard workflow. My workaround for situations where I find these artefacts unacceptable is to create worksheet/drawing and use Fill Consolidation to merge identical adjoining fills - a functionality that I think should be integrated in the publish process.