Recommended sand papers and files?

I recently purchased a Nicholson Double and Single bastard cut file. What file should I move down to next? Then sand paper?

Also does anyone recommend a certain brand and type of sandpaper?

Thanks!

Ryan

For sandpaper, I usually just use Silicon Carbide, it's kind of reddish in color. Now that's if we're talking sheets. If you mean belts, then it's ceramic all the way. As far as brand, i just get the stuff at the local hardware store, but gatorgrit, and norton seem to get good reviews. As far as files, i wouldn't be without a triangular file, and a half moon(half round? i forget the name exactly) at least. Good job going with the nicholson though, I usually buy mine at pawn shops and yard sales, the older ones seem to be better than the newer ones, but even the newer ones are still good.

3M silicone carbide paper is dark grey - available at hardware stores, big box home centers - at auto supply stores you can find it in higher grits - 1000 and up. I usually go to NAPA for the finer stuff. You can use it wet or dry - some folks use WD40.

Personally I don't like silicon carbide. I find it clogs up rather fast, compared to aluminum oxide.
I don't think the brand matters much. I find that aluminum oxide on linen has the best longevity.

As Bruno says, Alum. Oxide,is made specifically for steel.