Sandpaper coarseness is determined by the size of grit on the paper—ranging from extra-coarse to extra-fine. Using sandpaper that's too coarse could damage the material you're working with.

Grit numbers range from 24 (extra-coarse) all the way up to over 1000—though most home improvement projects use sandpaper in a much smaller range, from roughly 60- to 360-grit.

But sandpaper’s got you, friend—just scuff up the soles with some (approximately) 100-grit sandpaper. The sandpaper will take the smoothness off and leave behind a rough texture that will grip ...

A 100 grit sandpaper is considered the first of the smooth types. It’s great for hardwoods such as oak and it will sand down all the rough spots and make them reasonable smooth.

Generally speaking 30- and 60-grit papers are used for rough sanding, 100- to 150-grit sandpaper is for medium sanding and 220-grit sandpaper is used for finish sanding.

Generally speaking, 30-grit and 60-grit papers are used for rough sanding, 100-grit to 150-grit sandpaper is for medium sanding, and 220-grit sandpaper is used for finish sanding.

The best solution is to refinish the entire floor. But you should be able to significantly improve the way the floor looks without resorting to that.

Will sanding your grip act as a temporary band-aid? What I found was fine-grit sandpaper (100 grit and above) used gently can help roughen up the surface and lend more traction.

Usually 30-and 60-grit papers are used for rough sanding, 100-to 150-grit sandpaper is for medium sanding and 220-grit sandpaper is used for finish sanding.

You must remember to use very fine-grit sandpaper, and the porcelain must remain wet at all times. As long as the porcelain is wet, the sandpaper will "float" on the surface and will not scratch it.