not sure what "casual" material is (sorry) but I got my 3/4 sleeve white blazer from Old Navy last year and I love it. It has held up well too.
I did check Old Navy. They only white one I saw there had embroidery on the sleeve and a weird little breast pocket. I'm looking for totally simple...always seems to be hard to find simple....throw in a weird embellishment, super easy to find.
Ooh, I have one on hold at Banana Republic that I'm buying tomorrow with a giftcard. It is originially $198, but marked down to $29.99. The store near my office only had sizes 0, 2, 4, and six, but the web site has a lot more. The strange thing is, the site is listing the price as $130.99, but the site has more sizes. And you could probably do a price adjustment in a store or ask them about the price discrepancy and maybe they'll sell to to you for less.
I usually wear a 6 or even 4 in jackets and tops, but this was a smidge tight on the shoulders, but i'm chalking that up to the fact i had on a sweater that was bunching up at the shoulder.
that looks almost exactly like the one I got at ON last year except the sleeves are shorter and the length is a tad shorter. Wow. It is an awesome price if you can get a price adjustment.