Related question on snowboards' build quality.
I was sitting on a bus across from a snowboarder, who was holding his board in such a way that I had a perfect edge-on view of it. I noticed that the board's thickness was "lumpy" in a way that didn't look intentional. You expect skis and boards to be thicker in the middle and taper to the tips of course, but on this board (and I few others I've scoped out since), the taper wasn't a smooth slope - it had subtle but visible "wave" formations.
Is that intentional, or an example of a shoddy manufacturing process?
That's Magne-traction (and intentional). It's similar to a serrated knife versus a smooth knife. It works great, especially on ice.
1. Towards the bottom: http://www.lib-tech.com/snowboarding/technology/