This is a tasteful summer Nagoya obi
with abstractive cloud pattern, which is roughly woven with casual atmosphere.
Textile is summer sheer Ro silk, and it has relatively stiff touch.
Patinas(1st photo) on the stiff lining can be seen through the transparent textile, especially around the tesaki are prominent.
Though the figure says it's a discoloration, it's more likely mixed color threads.
For the details, please refer to the photos and the sheet.
It's no longer tie-able, but it is still enjoyable casually.