Naniwa Super-Stone/Advance Japanese Whetstone Sharpening Stone, 3000 grit Wusthof Gourmet it is generally flat and

it is generally flat and it's fine to use either side for sharpening (stick to using that one side though once you start)

and even many pro users now prefer a knife of this size instead of the old-school 10"

Or you can bring it to a professional knife sharpening service (a GOOD one that you trust

The perfect choice for someone looking for a traditional real Japanese usuba made in the traditional manner out of the highest grade Japanese carbon steel: Aonikou

Naniwa Super-Stone/Advance Japanese Whetstone Sharpening Stone, 3000 grit Wusthof Gourmet it is generally flat andNaniwa Super Stone 3000 Grit Japanese Whetstone Sharpening Stone, NO Stand, 21cm x 7cm surface, 2cm thick. This fine stone is just the ticket for finishing off your edge, or for regular maintenance. It's a good option for people who don't need the more polished edge of the 5000 or higher grit (and this one will work more quickly, and it's cheaper). This is the smoothest most people will ever need to use for most average knives, especially German