Combination whetstone

How to sharpen a knife: Soak the whetstone in water until no air bubbles appear, and keep the whetstone constantly wet while sharpening. Place the whetstone on a dedicated stand or on a wet cloth to prevent it from moving.

Hold the knife as shown in Figure 1, and sharpen the knife while maintaining a constant angle to the whetstone. As shown in Figure 2, position the knife so that the angle between the knife's cutting edge and the whetstone is 45-60 degrees.

Double bevel knife: The angle between the whetstone and the knife should be about 15 degrees, as shown in Figure 3.  

Single bevel knife: Place the blade on the stone as in Figure 4.  

Sharpen the knife by moving it back and forth, using the full length of the whetstone, with just enough force to lightly carry the weight of your arm without exerting too much pressure. When burrs appear, sharpen the other side in the same manner until burrs appear.
For single bevel knives, see Figure 5 for the knife angle. Once burrs have developed along both sides, spread newspaper on a flat surface and rub both sides of the blade to remove the burrs.

In order to continue sharpening accurately, use a flattening stone to flatten the surface of the whetstone.