alenka wrote an answer about Arc'teryx Theta SV Bib - Women's on October 26, 2013
Hi there, I just came back from the arcteryx store here in vancouver, bc where I was trying on the theta bib and tough luck on the sizing. With arcteryx products, small always fits perfectly but with these pants I found S to be a but too baggy around my waist and bum. I tried on an XS and while waist was a nice flattering fit the hips were too tight in XS. It also depends what you typically wear under your ski pants. If a pair of light-medium weight long johns then I'd say a Small will be all right.