Nagoya-Obi is the most used Obi type among all types of Obi. It is normally worn only in the Ichiju daiko musubi (letteraly means “one layer drum knot” and it is common taiko musubi knot) style, but tsunodashi knot is also popular as a natty style.
Nagoya-Obi is often explained as “one end to wrap around the waist is folded and sewn in half”, but unsewn Nagoya-Obi is also commonly seen. This explanation is correct in the light of historical background, but to judge if your Obi is Nagoya-Obi or not, you should see the length of Obi.
The length of Nagoya-Obi is approximatively 3.5m and it is shorter to tie Nijudaiko-Musubi or two layer Taiko-Musubi knot. Nagoya-Obi can be used in different ocassions. As there are a wide variety of types of patterns and textures, we often hesitate which to choose. Basically, you can choose if an Obi goes well with Kimono. For exemple, when you use casual and pretty Nagoya-Obi for Homongi Kimono, the Obi may looks sleazy.
On the other hand,a classical pattern Nagoya-Obi made from exquisite brocade which can be accepted as semi-ceremonial wear, may be too prominent for a Tsumugi type Kimono.