Board Thread:Skyrim/@comment-138.130.232.179-20150701081024/@comment-29458028-20160410013408

Eh, maxing out light armor skill without crafting will give at most 300 plus (less than 350) armor rating even for dragonscale (most other unimproved light will die at the high 200 rating). It's not too bad, but this can mean you are taking double damage or even triple damage compared to a max crafted set.

It will still give protection, somewhat. But hitting the armor cap without smithing is an impossibility. Even heavy armor won't go past 430 rating without smithing. And a lot of legendary rated heavy armor won't reach armor cap without a fortify blacksmithing potion. (Only Daedric, Dragonplate, Ebony will.)