Absolutely the best shirt Ive ever bought. I was out in the sun in 100 degree weather all day and didnt sweat a drop. I actually had people coming up and feeling my shirt because they couldnt believe it. Of course I also had lululemon shorts and underwear on. Still not one drop of sweat showing. If I wouldnt have been wearing the clothes I would of never believed it. It took me a while to switch to lululemon but I wont wear anything else now. Thanks lululemon keep up the good work and good clothing