The word "welt" typically refers to a raised, red mark on the skin caused by an injury or irritation. It can also mean a strip of material sewn onto the edge of a fabric for reinforcement or decoration. Full definition
Cuffed cotton shorts with red and white stripes, loops, zip fastening, hook and button fastening, two italian pockets, two buttoned back welt pockets. (vestiairecollective.com)
She said she often came home with welts on her hands until she learned right handed cursive properly. (makingahouseahome.net)