Knit set!! For this main set I would say it is TTS. I am happy with my XS top and bottom, but if in between I would size up For the other sweaters and sweatpants they run a bit big so if you prefer a baggy fit, TTS but for a tighter fit size down!! Got XS sweatpants and could have done XXS LTKfindsunder100 LTKfindsunder50 LTKstyletip