This is a Hon Fukuro obi
with admiring 'shou-chiku-bai'( pine tree, bamboo and ume blossom) pattern, which is woven colorfully against black base color.
Textile is silk, and it has soft touch.
Length is 410cm (13'5"in), rather short for Fukuro Obi.
Actual color is darker than shown on photos.
Stains mentioned on drawing image are more like spots of mold, and they are rather noticeable especially on blank part and its lining. (thrid photo below the drawing image)
Snags on Otaiko pattern (second photo below the drawing image) may show when tied.
Fray mentioned are snags. (fourth photo below the drawing image)
It has some other flaws, such as a folding line and discoloration, as shown on photos.
Please see photos for details.
If you do not mind the flaws mentioned, it can continue to be worn.