Woodworkers use great care in cutting and assembling their projects. They should exercise the same care when choosing the right type of abrasive materials. The right sandpaper will make sanding faster, easier, and give you smoother finishes.The following are the more commonly used types of abrasive materials:
Flint paper is a medium-hard grit that is recommended for course work such as removing paint, etc. It is used primarily on soft woods and is not very useful for finish work.
Aluminum oxide paper is recommemded for sanding hard woods and metals
Garnet paper is not quite as hard as aluminum oxide and is very brittle. The brittleness causes it to be self-sharpening and fairly durable. It is one of the most popular choices among woodworkers.
Silicon carbide paper is an expensive, quite hard paper that is good for sanding all types of metals and for smoothing finishes on woodworking projects.
Emery cloth is inexpensive and recommended primarily for smoothing metal.
Crocus powder is medium-priced and very soft. It is usually ground to a fine powder that is used primarily for metal polishing.