This question already has an answer here:
- Strange bordering in Illustrator 2 answers
This seems to be a recurring problem when cutting shapes directly in half when using Illustrator's 'Divide' tool. While the shape may look ok in the program itself when I output it as a png or reduce it to a smaller size in a raster-based program like Photoshop a white line appears right down the middle. Is there a better technique to avoid this?