Early in my turning years, a guy told me the 2000 grit line. I used it
to burnish Christmas ornaments. I got over it.

Grocery bags have two problems: 1 - they don't grade the grit to any
standard I know. I doubt if the paper mills share their brown bag
recipes with each other to gain consistency. 2 - The grit of any one
bag is probably quite variable from the coarsest to the finest grits.
I pay good money to know that my 1000P paper is within +/- a few gritss
of that size.

Besides, brown bags suck for wet sanding.

Joe Fleming - SAn Diego