- Design: SMFK Retro Collection utilizes vintage-style materials and finishing processes such as garment dyeing/stirring/salting/stone washing to present the retro texture of the clothing. SMFK wide-leg track pants are inspired by retro paratrooper pants, transformed into athletic wear. They use retro fine twill workwear cotton and a washed finish, featuring a left pocket and an embroidered cross logo.