Sandpaper for lapping a 3x3 30k Shapton Slip Stone?

[Arkwell]

Guys, I have a 3x3 Shapton 30k Slip Stone that I want to lap. I have a flat piece of glass to lap on, now I just want to know what kind and grade of sandpaper I need?

 

[smalltank]

dmt325 diamond plate works well...I think 400grit sandpaper is also an option to lap your stones.

 

[alpster]

I use 400 wet paper on a certified flat granite surface plate to lap my Norton stones. Works beautifully.

 

[PapaFish]

I use Harbor Freight sandpaper. The variety pack of wet/dry. It goes from 220 up to 1200. I typically take my stones all the way to 1200, just because I can. On my CNat, the difference between 500 and 1200 grit is noticable in the edge it gives. YMMV.