In Japan it is common to sign any document with a tiny stamp instead of using a pen. The signing space on the Japanese documents is usually small because this personal name stamp is used. It is called a hanko. Or inkan. Or maybe the tool is called a hanko, and the stamp itself (applied on paper) is the inkan. It is quite the same thing. There are so many types of hanko. It can be made of wood or metal, it comes even in red or green, it is round or square. Maybe the square ones are used more in business environment, and the round ones are less official and more “personal.”
Everybody in Japan is likely to have at least one such stamp. Some people have more than one inkan. As far as I know, one must register their inkan in order to use it officially. Of course, the surname written in kanji is there. I have heard of foreigners who live in Japan even for years without having an inkan. Such “abnormalities” are understandable with foreigners. :-p Then, there are inkan written in katakana for foreigners – it is such a welcoming feeling towards foreigners in Japan in general.
The price varies according to the material it is made of. I have read about an inkan made of mammoth tusk that costs more than 1 million yen. ^ ^ Though the average price is about 20 euro.
Some years ago, I received a wonderful present – my own inkan. Somebody thought a lot about the proper kanji based on my name. ありがとう ございました, 春田様。
The inkan is small, about one finger size.