Fine lines appearing in my adobe illustrator design (saved as jpg no lines) but appear in indesign

[Lisette3073520517cq]

Please help

I'm creating a portfolio of work and have pages set-up with no errors in my adobe illustrator designs - These are then saved as jpgs (page) to be used in Indesign to convert to a pdf document (so several pages). When open my saved jpg pages the files are fine - no design (fine lines show in my patterns). BUT When I place my "jpg" into indesign some of my designs suddenly show fine lines which were not visible in the original jpgs.,nor are there errors in my orignal swatches (repeating pattern). Am totally baffled. Can anyone help with this issue, Thanks in advance.

[Peter Spier]

First, what you see in InDesing is a display preview that is also a jpeg derived form the original file and you should not judge the output from the screen in InDesign. Expoerr your PDS and look at that.

Second, instead of exporting .jpeg from Illustrator, either save as PDF from Illustrator and Place that, or Place the original .ai file. You'll get far superior quality.

[Lisette3073520517cq]

Thank you .. my experience with inDesign was a new experience and with your suggestions my problem was resolved. I think it was my inexpeience more than anything so appreciate your help. I also ended up making a pdf straight from Abode Illustrator - with artboards laid out as I wanted them displayed, in one file to convert. 

Incidentally - the lines were appearing in many of my designs - in my repeat as a result of me using colours at 40% and less opacity. I managed to correct the lines from showing my making my repeat bounding box slightly larger and this resolved my fine lines.

Weirdly this seemed to occur with most recent update in Adobe illustrator. I say this because my original designs did not have this issue, and when I went back into them only ones with opacity (in my motifs going over bounding box/artboard for repat patterns) were showing fine lines (in the past older versions - this issue wasn't there).

Again thank you for your help/suggestions. Sorry to only get back to you now.

[Michael Bullo]

Is there a particular reason you are first exporting out JPEGs? I absolutely agree with @Peter Spier that placing the Illustrator files directly into InDesign is the way to go.

[Lisette3073520517cq]

Appreciate your help I have resolved the issue - see my reply to Peter Spier.

[Michael Bullo]

Thank you. Happy designing.

[Willi Adelberger]

Those lines come from the stitching lines when transparency is flattened. These will be visible with JPG, EPS and PDFs with flattening. 

When you use Illustrator content in InDesign save as AI or PDF/X-4 files. JPG is a bad choice as it does not support transparency and its compression causes spotty areas. It converts vectors in rasters, another problem which reduces quality. 

[Peter Spier]

@Willi Adelberger , while I agree there is a strong possibilty of stitching artifacts, we can't presume that's what the OP is seeing in this case. She (?) says the lines are not visible in the original jpegs, and mentions pattern fills, which to me implies tiling and my suspicion is the InDesign preview is showing lines at the tile borders.

[Lisette3073520517cq]

Yes that is exactly what was happening - while not showing in Adobe illustrator or on my own print tests - it showed up in InDesign. (My jpegs) I did resolve this by making my repeat tile slight larger to allow for my motifs with reduced opacity to not show the fine lines and that resolved my issue in InDesign. I do also now know better than to use jpgs too! Thanks for steering me in the right direction, Peter and Willi - appreciate it!

My inexperience with iDesign was also to blame - but one has to try new things and I appreciate all of your help.