seam shibori

after cutting one velvet square from an old jacket, i noticed i cut into an old dart by mistake (?). i opened the seam and cannot believe it. what a find, like a fossil embedded in the fabric. i have decided to leave this in the quilt for it is appropriate for the forest theme and is a nice surface variation. i also think it turns out to be some  natural form of shibori which is a stitch resist method of dyeing. in this case it has been "dyed with age". i will now open up all the seams of my discarded clothing and use them in my quilts.