Black and Zebra files are both used for enhancing the overall shape and appearance of the nail.
Black abrasive paper is typically made with a silicon carbide grit and suitable for immersing in water or other disinfectants during the cleaning process. Silicon carbide is fast-cutting and almost as hard as a diamond.
Zebra abrasive paper is made with black silicone grit also and then coated with white zinc sterate powder. This substance acts as a lubricant to reduce heat from friction, keeps the filing dust from clogging in the grits and extends the life of the nail file. This paper comes in a washable and non-washable version.
Cushioned nail files provide a better grip and ease of use, they also allow more control and faster refinement of the nail.