Fabric
The Collins is designed for knit fabrics. You will need a fabric with at least 25% crosswise stretch. It looks great in jerseys, rib knits, ponte knits, scuba, and more! If you are sewing the dress version, a fabric with a bit of body will hold the shape of the hem nicely.
Notions
1.8m of 19mm-26mm elastic (for the shelf bra hem)