I have an object in Illustrator with a chevron pattern that I created in Illustrator. When I export as a .png file or rasterize image file, it shows horizontal lines.
Anyone have a clue why it does this? I am at a complete loss. It's not the seams of the pattern.
Below is a .png file export of the image:
Be certain to export with Art Optimized anti-aliasing selected.
Note the hairlines coincide with the dashes on the right. It's a flattening issue which Art Optimized will most likely solve.
If possible, placing a solid, pink-filled shape behind the chevrons would also probably solve the issue by providing the color which Illustrator should use to anti-alias.
This is one of those things with patterns in AI that irks me... poor anti-aliasing.
My solution was to save as a PDF, open it in photoshop and save it as the raster image. I believe it was poor anti-aliasing as @Scott suggested, which Photoshop handles much better. Art optimized did not improve the issue. It's not an idea solution by any means, but it does work.
The only fool-proof thing I have found is to use Art Optimized and export as TIFF. In a test that I did recently, only the TIF export format removed the lines.
I spent a lot of time trying to avoid this "white lines" problems.
I just find this and it works for me: http://fashionclassroom.com/blog/fixing-lines-in-illustrator-patterns
I find the solution for me in step 4: duplicating the shapes which are on the lines and they disappear!
Can be some rasterization error. Can't say about reasons for sure, BUT you always can export it with much higher resolution as you need and then downscale the raster to necessary size. I am sure lines will be gone.
It looks like you built a grid, then made the Chevron pattern on the grid.
To fix this, select your pink shapes all together by using the lasso tool or direct selection tool by holding shift while you click the shapes to add them in the selection.
Bring up the Pathfinder tool box, by going to > Window > Pathfinder. In the Pathfinder box > Merge.
This will get rid of the lines because it'll make it all one merged shape, not a series of smaller shapes.
In my experience using Illustrator CS6, the lines disapear when exporting the artwork to high quality pdf. So I stopped bothering with the little white lines.
