Pants Line is a term used to describe the lines that are created when pants are made. The most common lines are the SEAM, inseam, and CREASE. The SEAM is the line that runs along the outside of the pant leg, connecting the two legs together. The inseam is the line that runs along the inside of the pant leg, connecting the crotch to the bottom of the pant leg. The CREASE is the line that runs down the center of the pant leg, creating a sharp, crisp look.