Mayday games calls them "magnum copper" but I'd stay away from their colored versions as they were too tight. If you favor a heavier sleeve Ultra Pro makes a thicker sleeve in this size like the heavier FFG sleeves.
I have also found that the Mayday colored 7 Wonders sleeves have been incredibly sticky (not like static, more like glue). I have still been using them, and encouraging players to make sure they have all their cards, but I think I'm going to have to unsleeve and possibly try something else. The clear sleeves of that size (which I use for Leaders) seem not to have the stickiness problem.
Mayday's are good choice - cheap and still working after much more than hundred games. And I can confirm they don't stick (clear ones).
Nine plays with clear Mayday sleeves here (bought at Starlit Citadel in Vancouver, BC). No problems.
I agree about the clear maydays. I've had no problems with them (other than the occasional too small sleeve that you just toss out...when you're getting 100 for three bucks, you don't complain about that.)
I was, however, disappointed with the mayday colored sleeves that they made specifically for 7 Wonders. They were flat out too small and I had to pitch them entirely. Wasn't worth the hassle of sending them back considering the cost.