Sandpaper sheets

What's the difference with other sandpapers ?

Silicium carbide is sharper and harder than standard forms of aluminum oxide. It has needle-like grains that resemble shards of broken glass. These hard, sharp grains cut glass, plastic, and metal well under light pressure, but silicon carbide is not a tough mineral. Its elongated shape shears off easily, making it too friable for bare-wood sanding because the abrasive wears down too quickly, according to manufacturers. It is, however, an excellent choice for smoothing a finish between coats and for rubbing out film finishes like lacquer and shellac, because it cuts quickly and produces a uniform scratch pattern.