This is an interesting ribbon because, besides being a nice plaid, it gives us a chance to look at a few different things. The most obvious is the damage water staining can do to silk. There are several spots throughout this ribbon. Next is the plaid itself. Notice the plaid is on the grain. For bonnet ribbons, you do not want plaid cut on the bias. (The curtain/bavolet can be cut on the bias.) If you can look close at the ribbon (check in the lower right of you Explorer window for the zoom feature), take a look at the subtlties the change in weave can enhance the lines. Next look at the wider blue and wider brown areas. These have a varigated look created with gradiated tones of warp threads. In modern terms we call this ombre.