While there are different models of punching bags, synthetic leather coverings are gaining popularity over both real leather and cloth. This material tends not to stain or tear as easily as cloth, and it is more affordable than real leather. (See Reference 1). When it does tear, there is a simple method that quickly can cover a tear and prevent any further damage. Many of the materials needed are common household items used for other chores and projects.
Cut away any frayed edges, loose strings or small obstructions that could get in the way of the tape sticking to the bag.
Measure the length of the tear and cut off a slip of duct tape that is slightly longer than the tear.
Place one end of the tape at the beginning of the tear. Slowly drag your finger down the tape, sticking it securely to the bag.
Gently rub a small piece of sandpaper against the tape if it has a glossy finish. Be careful not to scuff the bag.
Dip the paint brush in the can of paint and cover the tape with it. While a single coat should be sufficient, you might want to cover it a second time so that it blends in better.
Most synthetic leather punching bags are black, but if you own one that is another colour, buy similarly coloured paint.