Fabric
The Twin Lakes Two Piece is designed for knit fabrics. You will need a fabric with 4 way stretch and at least 50% crosswise stretch. If you are making this as a swimsuit, you will need swim fabric and because the swimsuit is not fully lined you will want to make sure your fabric is opaque.
Notions
1.4m of 1cm wide elastic - For the straps
1.4m of 1.3cm wide elastic - For the waistband on the top
9.5mm lingerie strap slides and rings set