So my Smithing is at 40, and I have Leather Armor that I improved to Superior. I want to improve it again, but I don't have the option to. It's grayed out. I only have the Steel Perk in the Smithing tree. (There's no perk that mentions Leather or Fur...)
When do I get to improve the Leather armor again? Is it at a higher level of Smithing? Or is there a Perk that I need? This is assuming that I can improve it at all.
Thanks in advance.

. Iron and Leather don't upgrade as everything else, it's a real pain. If you're on Xbox or PS3 you're stuck with it but on PC there is the Legendary Smithing mod which corrects this anomaly
!!