A principle of Ooshima tsumugi

There are many kind of Tsumugi textile in Japan.
also There are fake one too.
I can let you know How can you find real one out.

1. All of product must be 100% silk.
2. It must be a yarn dyeing from doro some and hand weaving.
3. It must be plane weave.
4. A splashed pattern is made by Shime bata( in which special weaving loom for dyeing )

If you can find Ooshima tsumugi which cover the principle 1~4
you can find this trademark of  on product.
Its called "Tikyu shirushi" means trademark of the Earth.
It promise you that is is a proof of high-end brand in Kimono textile.

If you will find similer trade mark
it means its include camical dyeing and machine weaving.

photo by http://blogs.yahoo.co.jp/jyuzakenji/49949196.html