5 Replies Latest reply on Oct 26, 2009 9:39 AM by shunithD

    Hairline edge

    KC29 Level 3

      I think I've seen the answer to this before somewhere several years ago........


      Look at the example I've attached. I've created a curved clipping path to mask the red and blue area, but I'm stuck with a hairline red edge. Looks like a small stroke but I've checked and there definitely isn't one


      Any suggestions how to get rid of it?

        • 1. Re: Hairline edge
          Jacob Bugge MVP & Adobe Community Professional



          When I open the PDF (in Acrobat 5, viewed on a Brilliance 109P, the best CRT I could get hold of to replace my Trinitron Multiscan G420), and zoom in to 1600, I see no hairline. At intermediate zoom levels (round 200 - 400) there seems to be something at the rounded blue borders, but it could look like some screen artifact. How does it print?

          • 2. Re: Hairline edge
            KC29 Level 3

            Thanks for your reply.


            When  you said you can't even see what I'm referring to, it made me remember a possible answer


            Looking at Acrobat > Preferences > Page Display > Smooth Line Art ..........


            if that is un-checked the hairlines disappear but the artwork looks very jagged


            If that is checked the artwork looks smooth but the hairline is visible


            And it doesn't print whatever the setting


            But it IS visible as a  hairline on the Illustrator artwork

            • 3. Re: Hairline edge
              Jacob Bugge MVP & Adobe Community Professional



              I just opened the file in Illy (10), and the hairline shows clearly, with the same apparent stroke weight regardless of zoom level, up to 988%. From 989% up, it is gone.


              So, as with the PDF, it only shows up to a certain zoom level.


              I do not have that Preferences option in 5.


              So it seems it is a screen (rendering) issue.

              • 4. Re: Hairline edge
                JETalmage Level 6

                I would not trust those hairlines to be just screen-drawing aberations. The artwork needs to be simplified.


                Use your white objects to punch (Subtract From Shape Area, Expanded) the red and blue objects. When you do this, you'll find that paths are left along the problem edges, even where the white object clearly laps beyond the edges of the blue and red (suggesting something wrong with the file).


                Don't use all those overlappng clipping paths. Simplify the artwork down to "literal" paths shaped like what you want to see.


                Also: Although I don't think it's the cause in this case, be aware that bugs in some of Illustrator's Pathfinder operations do, in fact, result in hairline strokes (which Illustrator isn't even supposed to be able to create). The presence of these is easy to overlook because of Illustrator's antialiasing--but they can wreck a print job.



                • 5. Re: Hairline edge
                  shunithD Level 3

                  Not visible in (Acrobat) Reader 9


                  Visible in Illustrator CS3 and CS4


                  Ok... just reduce the path a fraction (and i mean a fraction - it won't affect the art)... it vanishes. You'll still get it on the right side. Then, reduce the width of the clipping mask a fraction as well and that vanishes...


                  Basically, there seems to be a slight mismatch between the clipping mask and the art... someone please correct my explanation...


                  Edit: Correction. It shows in Reader... but i didn't catch it on the secondary monitor. Also, it's fainter than in AI but it's there.