White lines appearing in my illustration - what's wrong, and how do I remove it?

[noah23407020fvx6]

Hello!  

I've been struggling with this one pesky problem in this dog illustration I'm making: when I clip the black spots onto the white dog beneath, this thin white line keeps appearing at the edge of the image.  It may have to do with illustrator's anti-aliasing feature, because when I turn it off the line goes away - but then the illustration becomes a choppy, pixellated mess that I  can't use.  Is there a way I can get rid of the white lines while keeping the anti-alias intact?  Thank you! 

[Ton Frederiks]

Noah, can you show an example?

It looks like anti-aliasing what you are describing.

This won't be visible when printed at high resolution, what is your intended use, print? screen?

[noah23407020fvx6]

whoops, I thought I attached some pictures!  here you go, these  should show the issue:

[Ton Frederiks · Accepted solution]

Thanks, often these are visible when objects touch each other.

The line in the ear can be solved by joining the grey parts, Pathfinder Unite or dragging with the Shape Builder tool.

The blue background can be replace by a single blue rectangle in the background.

Before exporting as an image, Rasterize the file with Art Optimized anti-aliasing may also help. Best done as an Effect or on a copy.

[Bill Silbert · Accepted solution]

If you either print the illustration or make a PDF does the white line appear? If not then try turning off GPU Performance in the Performance section of Illustrator's Settings (Preferences).

[Big3840215634di]

actually useful

[xelop_7258]

I fixed this by just separating the object that caused the problem into a completely new layer.