I love obi - those wide "sashes" that secure Japanese kimono. The designs and colours are exquisite and they can be used for all sorts of things. Diane and Ann Wiltshire's "Design With Japanese Obi" is very inspiring.
I have just acquired a book containing 600 Japanese obi silk thread samples which I believe is probably from the 30-40s. The amazing thing is that the samples are all different colours and tones which explains how the Obi makers were able to achieve such subtle, yet spectacular, designs. Here are a few pages from the sample book.
Which explains how these were achieved...