This is 100% silk monofilament thread from Japan. It is possibly vintage. There is no labeling, so the manufacturer is unidentified. It is put up in skeins that vary in size, but are all about 3 ounces. 

This thread was made for embroidering kimonos and the like. It has great natural sheen. It is very fine and should be handled carefully, but it is quite strong. 

Fiber: Silk
Weight: 3.0 oz, 85 g (more or less)