What cord do you use for all around knotting? And, does anyone know what cord Clifford Ashley might have used. He must have always had some in his pocket.
Welcome to the forum @JAC.
It depends on what one is knotting, at work I would say 10-12 mm polypropylene or similar. At doing decorative knotting at home it would be 3-10 mm natural fiber rope, occasionally paracord.