“Wa” or Japanese handle
Wa is the typical Japanese handle where the knife tang goes in the handle material. It usually consists of two parts, a ferrule and the main body which are made from wood. They are light and that means that they move the balance of the knife forward (blade). There are three variations.
Octagonal (on the middle of the pic) wa handle is probably the most famous as it has 8 facets designed in a way that they offer high grip when on hand.
“D” shaped (on the right of the pic) wa handle is round but shaped with a small edge in the right (for right-handed) side of the handle this offers a comfortable grip but also gives something to index and grip in order to lock the knife in place.
The Round wa (on the left of the pic) handle is as plain as it sounds, a round or little bit oval handle, and offers the most comfortable grip of all but lacks the grip of the other two.
“Yo” or Western handle
Yo is the typical European knife handle where the tang of the knife extends all the way to the back of the knife and two scales of handle material are attached on the sides. It usually has a metallic bolster and the scales are attached and secured with pins. It offers a very comfortable grip and the synthetic materials used for the scales need essentially no maintenance.
There are several different blade type finishes to choose from and many blacksmiths combine different techniques to produce unique visual effects. These do not offer any cutting advantage in the knife but some of them can add some food release due to the dents/pockets they have.
Nashiji (Pear skin)
This finish is achieved by spraying powdered iron on the blade and this gives unfinished, rustic look!
Kurouchi (As forged)
Kurouchi is scale which is a byproduct of heat treatment of the knife. It gives a pleasing black textured finish.
Hammered either by hand or power hammer this finish gives unique look and some food release.
This finish is the most expensive of all as it requires materials and it is time consuming.
Damascus is the technique of folding two metals to form an eye pleasing result. There are many patters to choose from and each one is unique!
Note: In many cases we can find on the same knife combinations of more than one finishes.