Making your straps adjustable is an easy and professional touch to add to your bra. They are useful if you like to tighten or loosen your straps from time to time. As your bra ages, you can also tighten your straps as the bra strapping can lose elasticity over time, so adjustable straps will prolong the life of your bra.
Firstly, you will need to cut your bra strapping to the size specified on the pattern for your size. You will also need to cut 2 smaller pieces of strapping that will hold the rings. These are usually 3.5cm or 1 1/2″ long. Your slides and rings should be the same width as your bra strapping. Test them first, the strap should slip easily through the slide.
Thread the smaller bra strap pieces through the rings, and fold the straps in half. You should have notches on the back pattern piece that indicate the placement of your straps. Sometimes it is hard to transfer these markings onto lace, so I like to use a fabric marker or white tailors chalk if my lace is a darker colour. Position the folded straps upside down on the right side of the back. Line up the raw edges to the top edge of the back. Pin or clip the folded straps and then sew a line of stitching 6mm or 1/4″ in from the edge.
Thread one end of the long straps through the middle bar of the slides. Shoulder strapping will sometimes have a plush soft side. This is the wrong side that will sit against your skin. Make sure you thread the straps with the right side of the strap facing out. Pull the strap through approximately 2cm or 3/4″ and stitch the end down. Trim the end of the strap to neaten.
Now thread the other end of your long straps through the rings coming from the back through to the front.
Take the end of the strap you have just threaded through the ring, and slide it up through the lower section of the slide, and then over and through the upper section of the slide.
Your adjustable straps are all done!
You will need the position the straps facing down as shown before you sew your elastic on.