Microsoft didn’t publish the specifications yet. Based on experience, there is a chance they will never publish them at all; there are still no specifications for Windows 8. It often result into style inconsistence and breaking the visual weight of the icons, but that is another story.
However, we can say the following, based on how the icons look:
- The icons have sharp corners
- They are line style icons with 2px lines
- The icons are based on a 32×32 grid
From our experience, the more icons you create, the better they will get — no limit! We’ve been creating icons daily since 2005, and we still have room for improvement. So, we believe that our Windows 10 icon pack is way better than our Windows 8 icon pack, which is three years old. Windows 10 is the best icon pack we have at the moment.