Finish on the knife

Different manufacturers finish their knives in different ways. All of them are more or less polished, but the technique used to perform this process defines how the knife will look. Some of the finishes can have an effect on how the knife behaves in contact with food, for example whether it sticks to the blade or falls off it. The finishing process is extremely time-consuming and it is necessary that the person performing it be very skilled and concentrated during the entire process, otherwise the knife may lose its aesthetic appeal and look unprofessional.

TEXTURE

This term refers to concrete contours that can be felt when touching the knife. It used to be thought that kitchen knives had to be completely smooth and polished to prevent bacteria from lingering on the indented surfaces of the steel. Today, the methods of leaving different finishes that are created during the knife production process are becoming more and more popular.

TSUCHIME - hammer marks.

During the forging process, the blacksmith hits the steel with a hammer, changing its structure and shape, but also unevenness appears on the steel, which today is more and more often intentionally left on the blade. The makers state that these hammering marks not only look beautiful but also testify to manual engagement, i.e. forging. In addition to everything, they also have a functional element, the unevenness reduces the contact surface between the food and the blade, so the knife passes through the food with less resistance and with less friction. Another function is the creation of air pockets between the food and the knife that do not allow an absolute vacuum to appear and thus particularly starchy foods such as potatoes cannot stick to the knife.

KURO-UCHI - black texture.

This texture is also characteristic of Japanese knives and we often think of them as absolutely traditional. The Kuro-uchi finish is also called the blacksmith's finish and literally means: "first black". Appears after the knife is forged and tempered. Namely, the tempering process, which is performed by heating the blade to an extremely high temperature and then cooling it very quickly in water or oil, will result in the creation of a thin black layer on the entire surface of the blade. This is exactly what we call kuro-uchi. A part of this finish is removed by the grinding process, and the half of the knife closer to the "spine" remains black. This technique should be distinguished from ordinary painting with black paint or titanium coating because they are certainly not nearly the same thing.

NASHIJI- Japanese pear skin texture.

The name itself tells us, this finish resembles the peel of a pear, which is a bit rougher. Knives made in this finish are characteristic because the surface of the blade can hardly be scratched, precisely because of the aforementioned rougher texture, and this makes them a favorite among users. As with the kuro-uchi finish, the nashiji will be on the built part of the knife, that is, the part that is not sharpened. This texture is achieved by dusting the blade with a thin layer of iron powder before the final heating before tempering itself. When the iron melts, the knife is tempered and it retains its position on the surface of the knife. These knives are popular for their matte finish.

POLISHING

MIGAKI- satin finish

Migaki represents a slightly higher degree of processing, which we in Europe would call a satin finish. The surface of the blade has been polished just enough to show no traces of forging and steel processing, but it has not yet been polished to a mirror shine. The degree of processing will depend from manufacturer to manufacturer, with the rule that the rougher the migaki finish, the cheaper the knife, and the finer, the more expensive the knife. Some steels that are more resistant to abrasive action require more effort to achieve a uniform appearance of this finish. We can often notice that the knives are intended for more commercial use, made precisely in the migaki finish.

SAND BLASTING finishing

Although this is the more popular way of processing pocket and tactical knives, it can be seen from time to time on a Japanese knife. The most common case is to sandblast only a certain part of the knife in order to decorate it with an additional aesthetic element or to emphasize the difference between the steels. You have to be careful because this finish is very delicate, so it can be easily scratched but very difficult to repair.

BLACK OXIDE finish.

People have come up with countless ways to work steel. one of them is black oxide or chemical treatment. This type of finish results in a great contrast between steels with different nickel content so it's very good when we're trying to really accentuate the damask patterns. It is often used with mono steel, especially when making surgical tools. The surface that remains after treating the blade is extremely smooth and very easy to maintain hygienically. It is characterized by a typical black appearance, which is caused by the formation of oxides on the surface of the steel.

KASUMI - hazy finish

When we use a loosely bonded polishing abrasive that isn't strong enough to "cut" a particular steel, those abrasive grains end up just scratching the surface. This is seen in our eyes as "fog" and that is how it got its name. It is extremely difficult to find the right abrasives that will leave a hazy finish on one part of the steel and not touch the other, but that is why knives made with this technique are extremely valued. To achieve the best contrasts in the hazy finish, it is believed that the use of Japanese natural abrasives is necessary.

MIRROR POLISH - polishing to mirror shine

The extremely expensive and exhaustive process to properly achieve a mirror finish results in these knives being very expensive. To achieve the ultimate shine of their steel, manufacturers use a whole range of different grits and types of abrasives, progressing from the coarsest to the finest. If just one step on just one millimeter of the surface is skipped or performed incorrectly, the entire polishing process must start from the beginning. These knives are extremely sensitive, so it is necessary to clean them with very fine fabrics such as microfiber, and we must never use cleaning agents that contain abrasives. Although they look exceptional, these blades are rarely seen in professional kitchens because no one likes to scratch their perfect knife.

DAMASCUS

Polishing Damascus is all about creating a contrast between two different steels. Although some sellers list it as a type of finish, damascus refers to the construction of the steel, not the finish. By overlapping two types of steel, we get a surface that we further process with one of the above-mentioned polishing methods. Without polishing, even the best damask would remain completely invisible because there is no contrast. So, in order to notice the damask patterns on the steel, we need to treat it so that the two steels inside achieve two different finishes. The most popular and easiest way is to use chemical means, i.e. acid, but extremely beautiful damascus contrasts can be achieved by migaki polishing, mirror polishing, sandblasting or kasumi.