The Clean Cotton Shorts by Theory feature a sleek side zip, side seam and back welt pockets, and crisp front and back creases for a polished, minimalist look. The Clean Cotton Shorts by Theory feature a sleek side zip, side seam and back welt pockets, and crisp front and back creases for a polished, minimalist look. Established in 1997, New York-based Theory creates cool, expertly tailored clothing from the finest materials designed to inspire how you feel, work, and live.