How to remove stubborn cylindrical pen prints from the sand layer

Wipe with a soft cloth dipped in some thinner material or gasoline.

Beads that are specially used to rub leather are dipped in a soft cloth. >>>More

If you can't remove it, if you rub it with a chemical solution that will damage the skin, the only way is to cover it up with a leather beauty cream of the same color, and then spray it with leather oil like new. FYI!

Leather sofa maintenance method Dirt: Wipe the surface with a soft cloth first, apply a little petroleum jelly, soak for a while, wipe with a cloth, do not wash with water or rub with gasoline. Greasy: >>>More

Egg white cleaning method.

After a long time, there are several places of dirt on the white leather sofa at home, which is particularly stubborn, which makes people have a headache. At this time, you can take an appropriate amount of egg whites, dip them in a cotton cloth, and repeatedly wipe the dirty areas on the surface of leather products such as leather sofas. This method is particularly effective for cleaning leather goods, and the egg whites also have a polishing effect, after which the leather will take on its original shine. >>>More