You can use any kind of background you want. Take the ties apart, remove the strip of interfacing that is in them, wash them ( gently) dry them { I use a mesh laundry bag for this step} then press them. Use a fusible lightweight stabilizer on the backs. Then use them anyway you want to. ( do make sure your iron temperature is set appropriately for the fabric ( silk for silk, polyester for polyester) ** silk and polyester are 2 very different fabrics**
A New, sharp needle in the appropriate size for the thread being used is important. I generally use a 60 wt. Thread * poly or cotton * when sewing silk (or finer silk thread) . the background can be what ever you want, regular cotton, flannel, wool, what ever.