Therefore many colleagues argue that it’s better just to use shapes rather than a combination of shapes and strokes for creating your artwork. Shapes tend to be easier to handle and you can play with additional effects, apply gradients etc. Well I partly agree. However there are a bunch of advantages if you use strokes such as that you get much crisper edges when scaling your icons. By default Illustrator aligns the stroke to the center, which is the main reason for those blurry edges.

In older versions of Illustrator you either had to play with the order of the several appearances in the respective palette or you had to use even numbers for your stroke’s weight to achieve crisp edges. Since Illustrator CS2 you may easily change the alignment via the three options in the “Stroke” palette. Spot the difference.