Price: 500 INR
Shoelaces with a flat cross-section are generally easier to hold and stay tied more securely than those with a round cross-section due to the increased surface area for friction. Very wide flat laces are often called "fat laces". Leather shoelaces with a square cross-section, which are very common on boat shoes, are notoriously prone to coming undone.
Shoelaces can be coated, either in the factory or with aftermarket products, to increase friction and help them stay tied.