vector lines displaying inconsistently

[KieranBrennanDublin]

Hi

I'm drawing a simple grid in Illustrator. I've copied one simple line multiple times like a step-and-repeat, so I end up with a simple grid.

When I import to InDesign and then export a PDF for client viewing, it seems like the result is lines of different strenght, thicknesses?

When I open the illustration, take a screen shot and use this in my InDesign doc, it seems fine! But obviously I prefer to use the vector.

Please see screenshot for clarification.

Any advice appreciated, thank you.

[Ton Frederiks]

Could the Acrobat preferences be causing this?

Page Display > Enhance Tin Lines

[Bobby Henderson]

Are the lines getting rasterized (converted to pixels) at any point before the grid is exported in PDF format from InDesign? If the grid lines are being converted into a pixel-based image the lines may not be falling on the pixel grid precisely.

Another possible issue: any kinds of rectangular shapes (including some letters) may be turned into stroked open line paths within the exported PDF. This might apply if the line strokes of your grid were expanded into thin rectangular shapes. The results can make on-screen previews of such objects in PDF files look irregular (often too bold) unless the preview is zoomed in tight. Turning off the "compress text and line art" setting when exporting the PDF can fix that problem.

[KieranBrennanDublin]

Removing 'compress text and line art' unfortunately didn't work - however when I view the PDFs using Mac default pdf 'Preview' application, the lines display perfectly well!? So this might be something peculiar to Acrobat? Pity my client is viewing in Acrobat!

Workaround is for me to make a raster version and supply this for screen viewing and another version for print using the vectors.

Thanks for your suggestions.

[Ton Frederiks]

So this might be something peculiar to Acrobat? Pity my client is viewing in Acrobat!

By @KieranBrennanDublin

See my answer above about Acrobat Preferences

[KieranBrennanDublin]

Thanks for reply... here are my preferences for what I think you're referring to. It seems I do have that preference checked.

Thanks for any help.

[Ton Frederiks · Accepted solution]

Yes, if you uncheck it it should solve the problem.

[KieranBrennanDublin]

Wow, it does! Actually, oddly, no matter what I do now it works - perhaps something is 'cached' or whatever, but I can't seem to re-create the problem!

Thanks so much, I appreciate your advice, very useful tip.

[Ton Frederiks]

Good to hear that helped, unfortunately that preference setting is checked by default, so you will need to ask your client to turn it off.