I was finally able to get the elven armor smithing perk last night. I always like to see just how much of an improvement I get adding perks, so since I know one of the things the perk was supposed to do was "double improvement of elven items", I wanted to see what the improvement was before the perk.

I took the elven gilded armor I was wearing (41 armor), some quicksilver bars, and improved it at the work bench. That took it up to 47 armor. Not bad. I then went and restored from a previous save, got the eleven armor perk, and then improved the same armor. The armor was still 47.

Do I not understand what "twice the improvement" means? I would have thought after the elven smithing perk, that I could improve the armor to 53 armor.

I do not have any smithing or armor related mods on, btw.

The perks don't work by doubling the amount the armor rating increases when you improve an item.

They work in tandem with your overall smithing level by allowing you to get an item to a higher level of quality than you would've gotten without the perk given your smthing level at the time.

For instance, to get the item to Superior quality without the perk, you would need a smithing level of 31. If you have the perk, you only need to be at level 22 in smithing to improve an item to Superior. However you are not going to improve it beyond that point, even with the perk, until your overall smithing level goes up. You need a smithing level of 40 to get it to the next level (Exquisite), even if you have the perk for that material.

Ok, I figured I must have been misreading it. Thanks for the clarification!

No problem - it is rather confusing.

This may help as well:

http://www.uesp.net/wiki/Skyrim:Smithing#Item_Quality

The perk descriptions are a bit misleading. Here's some more specifc info of how smithing works:
http://www.uesp.net/wiki/Skyrim:Smithing

Thanks for the added info!