They are tts when you consider how they are designed to fit. The technical fabric is supposed to fit snug, but like others have said many people size up because they are uncomfortable with that.
What size should I get in swiftly Tech?
I would almost say its an in between sizing. You need to go up half a size LOL. When the size 6 was too tight the size 8 actually had lots of room. To me there seemed to be a big difference between the 2 sizes.
Do Swiftly Tech Long sleeves run small?
Fit / Sizing While I typically wear a size Medium for my long sleeve baselayers, I found the size 6 to fit perfectly, which Lululemon's size chart equates to a size Small. The fit of the Run: Swiftly Tech Long Sleeve is really great.Dec 6, 2014
What is swiftly Tech made of?
The shirt is made from a seamless synthetic fabric that incorporates Lululemon's trademark Silverescent technology with X-STATIC, which they explain inhibits the growth of odor-causing bacteria.Dec 6, 2014