Today we welcome Linda Crawford, a custom bra-maker, for a tutorial on how to make your own breast prosthesis.
There are lots of good reasons why you would want to make your own breast prosthesis. Here are a few…
- It fits your bra perfectly.
- You can make one for a fraction of the cost of a commercially made silicone prosthetic.
- It’s lightweight.
- It can be worn in for swimming and in the hot tub.
Commercially manufactured breast prostheses come in different shapes, but none of them is made exactly to fit your bra. They are made from medical grade silicone and they have a very natural feel to them, but many people find them hot and heavy to wear. If you enjoy swimming, it is recommended that you purchase a special prosthesis that will not break down in chlorinated water. And my friend Carol can attest to the fact that the silicone prosthesis does not fare well in a hot tub! It burst, the hot tub was drained, and everything needed a lot of scrubbing! A DIY version can resolve many of these issues.
What you need:
- Your bra pattern’s upper and lower cup pieces.
- Cut and sew foam — available from your favourite bra making supply store.
- Poly Pellets — polyester pellets available from crafting stores.
- Sewing machine and sewing supplies.
Let’s get started!
Step 1
Using your upper and lower cup pattern pieces, cut 3 of each from your cut and sew foam.
Mark the ¼” cross cup seam on all 6 pieces. Trim off the seam allowance on all pieces, at that ¼” line.

Mark the 3/8” elastic allowance on the under arm pieces and trim it off.
Step 2
You are now ready to join the upper cup pieces to the lower cup pieces. We removed the seam allowance to make this seam flat — so now butt the upper and lower cup together, and zig zag them together. You can use a regular zig zag stitch , or a 3 step zig zag stitch. The regular zig zag stitch results in a flatter seam. The 3 step zig zag makes it easier to catch both sides with the stitches. In my example I used the 3 step zig zag.
The sewn, shaped cup with the edges caught in the zig-zag stitch The 3 step zigzag up close
Prepare the other 2 cups the same way. You should now have 3 full cups the same size.
Step 3
Trim ½” from the perimeter of cup number 1. This will be the outside cup.
For the middle cup, you will trim of ¾” so it nests inside the outside cup.
For the inner cup, trim off 1”.
You should now have 3 cups, each one smaller than the last.

Step 4
Lay the largest cup on a piece of cut and sew foam, and trace the outline. This will become the backing piece that holds everything inside.

Repeat this step with the smallest cup. The smallest cup, together with its backing piece will hold the poly pellets inside.
Stitch the backing piece to the smallest cup with a zig zag stitch. Leave the neckline edge open.
Step 5
Fill the smallest cup with the poly pellets. I use a funnel to do this, but you can use anything that will direct the pellets into the cup.
Poly pellets, ready to go Smallest cup, one side open, with funnel
Before you close the opening of this smallest cup piece, pin it closed and try it inside your bra. Do you want it to feel soft, light, and squishy, or do you want a firmer and heavier feel? You can add or subtract pellets as needed. Zig zag the neckline edge closed.

Step 6
Hand stitch the middle layer to the outer layer. Stack the outer layer, the middle layer, and the smallest full cup, and test them inside your bra to make sure there are no additional adjustments to make.
Now, sew the large backing piece to the largest cup, leaving the neckline edge open.
Slip the small cup into the opening and stitch it closed.

The cup-shaped front of the prosthesis The flat back of the prosthesis
You are finished! The prosthesis should fit into your bra cup perfectly!

Linda is a (gifted) custom size bra maker and a kind person with a great sense of humor and a soft spot for cats, she lives in Burlington, Ontario, Canada, where she runs Uplift Custom Bras, her custom bra salon and sewing studio.
People from as far away as Australia, and as close as next door, have come for their own, comfortable, sexy, made-to-measure, wires never poking, custom bra.
