I can tell you if you start with Aluminum Oxide, you will be sorry, unless you have strong arms.

I made several up to 16x20 with Silicon Carbide that was quick and easy. (Well, the 16x20 does take many times longer than 4x5), I spent about 4 times as long on the Aluminum Oxide 5 micron only 8x10 than for SiC and I still can't get rid of the 'wavies'.

Regardless of the superiority of professional products like SatinSnow (which I really should try), I just like to make things...I hardly ever shoot film, unfortunately.

I haven't tried SiC first , then Alum. Ox. Maybe someday.