Symmes Strapless Bra
Defy the laws of gravity with the Symmes Strapless Bra sewing pattern!
The Symmes is built for serious support for big boobs in sizes 28C-54J, with vertical underwires, 4-pieces cups, and angled boning throughout to keep everything comfortably in place. Say goodbye to slipping, digging, and discomfort—and hello to a whole new world of wardrobe possibilities!
Created by curvy sewing experts and bra-making professionals, you can trust the Symmes to fit and feel fantastic as you dance the night away.
BONUS: Includes our Sew a Bra That Fits ebook free with the pattern download.
Overview
| Sewing level | Advanced |
| Sizing | 28C-54J |
| Cup sizes | C-J |
| Fabric type | Woven, bra fabric |
| Pattern hashtag |
PDF Info
| Delivery method | Instant download ZIP file |
| Layers available | Yes |
| Number of pages: print at home file (A4/letter) | 3-14 |
| Number of pages: copyshop file (A0) | 1 |
| PDF pattern help |
Pattern Options
| Cup lining | With, without |
| Boning at top of cup | With, without |
Fabric & Supplies
| Main fabric | Non-stretch woven fabric such cotton or rayon, or bra fabric such as duoplex. Fabric with a maximum stretch of 15% in one direction is acceptable |
| Lining | Non-stretch bra lining fabric such as nylon tricot or duoplex. NOTE: lining the cups is optional, but the lining on the center front band is required. |
| Bra foam | Cut & sew foam, 1⁄8” – 1⁄4” (3-6 mm) thick |
| Back band | Mid-weight stretch fabric such as nylon/spandex power mesh with 25–50% stretch in one direction and at least 10% in the opposite direction. For a more supportive bra, use a heavy-weight power mesh. |
| Band elastic | ¾” (19 mm) wide plush-back strap elastic |
| Bias tape | 1 ¼ yard (1.2 m) of 1 ¼” (3.2 cm) wide bias tape |
| Hook & eye | Continuous hook & eye tape with at least 3 columns of eyes. The number of hook and eyes are based on the wire size and range from 5 to 11 rows. |
| Boning | ¼" (6 mm) wide plastic boning with covering |
| Underwire channeling | Plush backed underwire channeling |
| Underwires | 1 pair of vertical underwires such as these from Porcelynne |
| Bow | Lingerie bow for center front (optional) |
| Needle | Universal needle, stretch needle (optional), hand needle to attach bow |
| Thread | Regular thread |
| Additional notions | Wonder Tape (optional) |
Model: Jenny
| Under bust | Full bust | Height | |
|---|---|---|---|
| Measurement | 38" / 96.5 cm | 48" / 122 cm | 5' 6" |
| Size | 38I |
Make This Look
Make This Look
| View | Strapless bra without cup lining |
Model: Rachel
| Under bust | Full bust | Height | |
|---|---|---|---|
| Measurement | 37" / 94 cm | 48" / 122 cm | 5' 5" |
| Size | 38I |
Make This Look
Make This Look
| View | Strapless bra |
| Fabric | African wax print |
Make This Look
Make This Look
| View | Strapless bra |
| Fabric | Super simplex |
Model: Brit
| Under bust | Full bust | Height | |
|---|---|---|---|
| Measurement | 30.5" / 77.5 cm | 40" / 101.5 cm | 5' 6" |
| Size | 30I |
Make This Look
Make This Look
| View | Strapless bra with cup lining |
| Fabric | Cotton Tana lawn |
Symmes Strapless Bra Sewalong
Sew the Symmes alongside Jenny and Jen from the Cashmerette team!
Why it’s special:
C-J cups
Incredible support & shaping for big boobs
More like this: Lingerie / Special occasion
The ultimate strapless bra sewing pattern for big boobs in sizes 28C-54J, with underwired 4 piece cups and angled boning. Free bra fitting ebook included!
Why it’s special:
C-J cups
Incredible support & shaping for big boobs
More like this: Lingerie / Special occasion
Adding product to your cart
Defy the laws of gravity with the Symmes Strapless Bra sewing pattern!
The Symmes is built for serious support for big boobs in sizes 28C-54J, with vertical underwires, 4-pieces cups, and angled boning throughout to keep everything comfortably in place. Say goodbye to slipping, digging, and discomfort—and hello to a whole new world of wardrobe possibilities!
Created by curvy sewing experts and bra-making professionals, you can trust the Symmes to fit and feel fantastic as you dance the night away.
BONUS: Includes our Sew a Bra That Fits ebook free with the pattern download.
Overview
| Sewing level | Advanced |
| Sizing | 28C-54J |
| Cup sizes | C-J |
| Fabric type | Woven, bra fabric |
| Pattern hashtag |
PDF Info
| Delivery method | Instant download ZIP file |
| Layers available | Yes |
| Number of pages: print at home file (A4/letter) | 3-14 |
| Number of pages: copyshop file (A0) | 1 |
| PDF pattern help |
Pattern Options
| Cup lining | With, without |
| Boning at top of cup | With, without |
Fabric & Supplies
| Main fabric | Non-stretch woven fabric such cotton or rayon, or bra fabric such as duoplex. Fabric with a maximum stretch of 15% in one direction is acceptable |
| Lining | Non-stretch bra lining fabric such as nylon tricot or duoplex. NOTE: lining the cups is optional, but the lining on the center front band is required. |
| Bra foam | Cut & sew foam, 1⁄8” – 1⁄4” (3-6 mm) thick |
| Back band | Mid-weight stretch fabric such as nylon/spandex power mesh with 25–50% stretch in one direction and at least 10% in the opposite direction. For a more supportive bra, use a heavy-weight power mesh. |
| Band elastic | ¾” (19 mm) wide plush-back strap elastic |
| Bias tape | 1 ¼ yard (1.2 m) of 1 ¼” (3.2 cm) wide bias tape |
| Hook & eye | Continuous hook & eye tape with at least 3 columns of eyes. The number of hook and eyes are based on the wire size and range from 5 to 11 rows. |
| Boning | ¼" (6 mm) wide plastic boning with covering |
| Underwire channeling | Plush backed underwire channeling |
| Underwires | 1 pair of vertical underwires such as these from Porcelynne |
| Bow | Lingerie bow for center front (optional) |
| Needle | Universal needle, stretch needle (optional), hand needle to attach bow |
| Thread | Regular thread |
| Additional notions | Wonder Tape (optional) |
Model: Jenny
| Under bust | Full bust | Height | |
|---|---|---|---|
| Measurement | 38" / 96.5 cm | 48" / 122 cm | 5' 6" |
| Size | 38I |
Make This Look
Make This Look
| View | Strapless bra without cup lining |
Model: Rachel
| Under bust | Full bust | Height | |
|---|---|---|---|
| Measurement | 37" / 94 cm | 48" / 122 cm | 5' 5" |
| Size | 38I |
Make This Look
Make This Look
| View | Strapless bra |
| Fabric | African wax print |
Make This Look
Make This Look
| View | Strapless bra |
| Fabric | Super simplex |
Model: Brit
| Under bust | Full bust | Height | |
|---|---|---|---|
| Measurement | 30.5" / 77.5 cm | 40" / 101.5 cm | 5' 6" |
| Size | 30I |
Make This Look
Make This Look
| View | Strapless bra with cup lining |
| Fabric | Cotton Tana lawn |
Symmes Strapless Bra Sewalong
Sew the Symmes alongside Jenny and Jen from the Cashmerette team!
Why it’s special:
C-J cups
Incredible support & shaping for big boobs
More like this: Lingerie / Special occasion
Body Measurements (in)
| Under bust measurement (in) | 28-29 | 30-31 | 32-33 | 34-35 | 36-37 | 38-39 | 40-41 | 42-43 | 44-45 | 46-47 | 48-49 | 50-51 | 52-53 | 54-55 |
| Band size | 28 | 30 | 32 | 34 | 36 | 38 | 40 | 42 | 44 | 46 | 48 | 50 | 52 | 54 |
| Full bust (in) | ||||||||||||||
| 31 | 28C | |||||||||||||
| 32 | 28D | |||||||||||||
| 33 | 28DD | 30C | ||||||||||||
| 34 | 28E | 30D | ||||||||||||
| 35 | 28F | 30DD | 32C | |||||||||||
| 36 | 28G | 30E | 32D | |||||||||||
| 37 | 28H | 30F | 32DD | 34C | ||||||||||
| 38 | 28I | 30G | 32E | 34D | ||||||||||
| 39 | 28J | 30H | 32F | 34DD | 36C | |||||||||
| 40 | 30I | 32G | 34E | 36D | ||||||||||
| 41 | 30J | 32H | 34F | 36DD | 38C | |||||||||
| 42 | 32I | 34G | 36E | 38D | ||||||||||
| 43 | 32J | 34H | 36F | 38DD | 40C | |||||||||
| 44 | 34I | 36G | 38E | 40D | ||||||||||
| 45 | 34J | 36H | 38F | 40DD | 42C | |||||||||
| 46 | 36I | 38G | 40E | 42D | ||||||||||
| 47 | 36J | 38H | 40F | 42DD | 44C | |||||||||
| 48 | 38I | 40G | 42E | 44D | ||||||||||
| 49 | 38J | 40H | 42F | 44DD | 46C | |||||||||
| 50 | 40I | 42G | 44E | 46D | ||||||||||
| 51 | 40J | 42H | 44F | 46DD | 48C | |||||||||
| 52 | 42I | 44G | 46E | 48D | ||||||||||
| 53 | 42J | 44H | 46F | 48DD | 50C | |||||||||
| 54 | 44I | 46G | 48E | 50D | ||||||||||
| 55 | 44J | 46H | 48F | 50DD | 52C | |||||||||
| 56 | 46I | 48G | 50E | 52D | ||||||||||
| 57 | 46J | 48H | 50F | 52DD | 54C | |||||||||
| 58 | 48I | 50G | 52E | 54D | ||||||||||
| 59 | 48J | 50H | 52F | 54DD | ||||||||||
| 60 | 50I | 52G | 54E | |||||||||||
| 61 | 50J | 52H | 54F | |||||||||||
| 62 | 52I | 54G | ||||||||||||
| 63 | 52J | 54H | ||||||||||||
| 64 | 54I | |||||||||||||
| 65 | 54J |
Fabric Requirements (yd)
| Fabric/notion | Band sizes 28-36 | Band sizes 38-54 |
|---|---|---|
| Main fabric - 45" wide | 1/2 yard | 7/8 yard |
| Lining fabric (including cup lining) - 45" wide | 1/2 yard | 7/8 yard |
| Lining fabric (no cup lining) - 45" wide | 3/8 yard* | 1/2 yard |
| Bra foam - 45" wide | 3/8 yard* | 1/2 yard |
| Back band fabric - 45" wide | 1/4 yard* | 3/8 yard* |
| Elastic - 3/4" wide | 1 1/2 yd | 2 3/8 yd |
| Bias tape - 1 1/4" wide | 1 yd | 1 ¼ yd |
| Hook and eye | 8 hooks high | 11 hooks high |
| Boning | 4 yards | 8 yards |
| Underwire channelling | 1 yd | 1 ¼ yd |
| Underwires | 1 pair vertical underwires | 1 pair vertical underwires |
*Will fit on a fat quarter of fabric
Body Measurements (cm)
| Under bust measurement (cm) | 72-76 | 77-81 | 82-86 | 87-91 | 92-96 | 97-101 | 102-106 | 107-111 | 112-116 | 117-121 | 122-126 | 127-131 | 132-136 | 137-142 |
| Band size | 28 | 30 | 32 | 34 | 36 | 38 | 40 | 42 | 44 | 46 | 48 | 50 | 52 | 54 |
| Full bust (cm) | ||||||||||||||
| 79 | 28C | |||||||||||||
| 81 | 28D | |||||||||||||
| 84 | 28DD | 30C | ||||||||||||
| 86 | 28E | 30D | ||||||||||||
| 89 | 28F | 30DD | 32C | |||||||||||
| 91 | 28G | 30E | 32D | |||||||||||
| 94 | 28H | 30F | 32DD | 34C | ||||||||||
| 97 | 28I | 30G | 32E | 34D | ||||||||||
| 99 | 28J | 30H | 32F | 34DD | 36C | |||||||||
| 102 | 30I | 32G | 34E | 36D | ||||||||||
| 104 | 30J | 32H | 34F | 36DD | 38C | |||||||||
| 107 | 32I | 34G | 36E | 38D | ||||||||||
| 109 | 32J | 34H | 36F | 38DD | 40C | |||||||||
| 112 | 34I | 36G | 38E | 40D | ||||||||||
| 114 | 34J | 36H | 38F | 40DD | 42C | |||||||||
| 117 | 36I | 38G | 40E | 42D | ||||||||||
| 119 | 36J | 38H | 40F | 42DD | 44C | |||||||||
| 122 | 38I | 40G | 42E | 44D | ||||||||||
| 124 | 38J | 40H | 42F | 44DD | 46C | |||||||||
| 127 | 40I | 42G | 44E | 46D | ||||||||||
| 130 | 40J | 42H | 44F | 46DD | 48C | |||||||||
| 132 | 42I | 44G | 46E | 48D | ||||||||||
| 135 | 42J | 44H | 46F | 48DD | 50C | |||||||||
| 137 | 44I | 46G | 48E | 50D | ||||||||||
| 140 | 44J | 46H | 48F | 50DD | 52C | |||||||||
| 142 | 46I | 48G | 50E | 52D | ||||||||||
| 145 | 46J | 48H | 50F | 52DD | 54C | |||||||||
| 147 | 48I | 50G | 52E | 54D | ||||||||||
| 150 | 48J | 50H | 52F | 54DD | ||||||||||
| 152 | 50I | 52G | 54E | |||||||||||
| 155 | 50J | 52H | 54F | |||||||||||
| 157 | 52I | 54G | ||||||||||||
| 160 | 52J | 54H | ||||||||||||
| 163 | 54I | |||||||||||||
| 165 | 54J |
Fabric Requirements (m)
| Fabric/notion | Band sizes 28-36 | Band sizes 38-54 |
|---|---|---|
| Main fabric - 115 cm wide | 0.5 m | 0.8 m |
| Lining fabric (including cup lining) - 115 cm wide | 0.5 m | 0.8 m |
| Lining fabric (no cup lining) - 115 cm wide | 0.4 m* | 0.5 m |
| Bra foam - 115 cm wide | 0.4 m* | 0.5 m |
| Back band fabric - 115 cm wide | 0.3 m* | 0.4 m* |
| Elastic - 19 mm wide | 1.4 m | 2.2 m |
| Bias tape - 3.2 cm wide | 0.8 m | 1 m |
| Hook and eye | 8 hooks high | 11 hooks high |
| Boning | 3.6 m | 7.3 m |
| Underwire channelling | 0.9 m | 1.2 m |
| Underwires | 1 pair vertical underwires | 1 pair vertical underwires |
*Will fit on a fat quarter of fabric
Make It an Outfit
Look Inside Our Patterns
Designed by curvy fitting experts
Our expert team crafts patterns specifically designed to fit and celebrate curves—because your body deserves clothes that work.
Sewing patterns made in your size
Band sizes 28-54 and cups C-J. Just choose your size using our bra fitting guide for the perfect fit.
Clear step-by-step instructions
Sew with confidence using our comprehensive instructions with clear diagrams and professional tips for every step.
Personal expert support
Expert help when you need it most. Our curvy fitting specialists provide personalized support to guide you through any challenge.
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Size Calculator
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Your Cashmerette Size Results
Our patterns are designed for curves in cup sizes C-H. If your cup size is smaller proportionally to your shoulders than our C/D cup size, you will need to do a small bust adjustment. To calculate how much width you need to remove from your pattern piece, divide the total SBA amount needed by two (as the pattern piece represents half the garment). How to do an SBA >
Our patterns are designed for curves in cup sizes C-H. If your cup size is larger proportionally to your shoulders than our G/H cup size, you will need to do a full bust adjustment. To calculate how much width you need to add to your pattern piece, divide the total FBA amount needed by two (as the pattern piece represents half the garment). How to do an FBA >
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We’re dedicated to helping you get a fantastic fit in our patterns, with one-on-one fit advice from our knowledgeable team.
Contact UsFrequently Asked Questions
Use our bra size guide to find your Cashmerette size based on your measurements, not your ready-to-wear size.
In addition to the pattern pieces, you'll get comprehensive instructions with step-by-step illustrations, multiple printing format options for PDF patterns (print-at-home and copyshop), layered PDFs for easy printing, detailed cutting layouts, and access to video or photo sewalongs for many patterns.
You'll also get our Sew a Bra That Fits: A Complete Bra Fitting Guide included FREE with your pattern download.
Absolutely! Contact us anytime with any questions. We're here to help you succeed with your sewing projects, and we love hearing from you!
This was my first time sewing a bra (apparently I like to try new things on hard mode) but having dabbled in corsetry before, it felt surprisingly similar. Only with a lot more elastic. I have made this one twice now and am overall very happy with the result.
In terms of creating a strapless bra that's actually supportive in larger cup sizes, this thing has NAILED IT. My hat is off to you, Cashmerette! It's honestly a little shocking how supportive this thing feels. My one quibble here (and I think I should be able to tweak this on further attempts) is that the cup shaping is a bit... boxy? It fits well and is very supportive, but I'm definitely wanting to adjust the way it contours around the body for purely aesthetic reasons. The cup bones also create noticeable ridges under thin/drapey clothes. Still, this thing is amazing for the simple fact that it does the job and stays up, and for that I can't give it anything less than five stars. I'm hoping with a few shaping tweaks, it will be perfection itself. I'm also very tempted to experiment with making a longline version — I suspect for my body shape it would be both even more supportive and more comfortable. (I often find the bottom of bra bands often cuts into my squishy bits below; this is not unique to this pattern. If this isn't a problem you normally have, that will probably remain true here.)
A note on sizing: I have always felt lied to by US bra sizing, because despite everyone SAYING that it's based on the under bust and full bust measurements, it actually seems to be one of the few cases where ready to wear uses the high bust measurement. If you go to a certain well-known US lingerie chain and have them take your measurements, they even measure the high bust despite their website saying sizing is based on under bust. So I have some trust issues around bra sizing, and it felt deeply weird making a 32G when I wear a 36D in ready-to-wear. Especially since I also make the D cup size for all the non-bra Cashmerette patterns. If you are in the same boat, I would say two things 1) plan to make a mockup or two regardless; this will likely want some tweaking no matter what because bras get funky 2) trust the sizing guide to give you a starting point. It may not be perfect, but it should get you close. I ended up sizing the cup down to a 32F but using the wire size suggested for the 32G. Your experience may be different. But I'm glad I went with the 32 band to match my 33" under bust — the size 36 band would have been way too big. So, yay for not being lied to about band sizing, but also it scares me a bit because I'm not used to it!
FIT & SIZING
• I sized down one cup because I’m shallow on top; the smaller cup eliminated gaping and gave a smooth upper edge.
• The wire line and cradle proportions are spot on — no collapsing, no slipping, and the bridge stayed anchored.
• Band tension felt balanced; no need to adjust band size.
SUPPORT STRUCTURE
• The structure relies on the foam cups, cradle stability, and strategic boning placement working together.
• I used plastic Rigilene boning not only at the sides and on the cup seams (plus and extra one) but also along the top edge of the cup, which made a noticeable difference in keeping the neckline firm and preventing any collapse or rolling.
• The cradle draft is strong — it distributes weight well and works with the foam to keep everything lifted without straps.
CUP CONSTRUCTION
• I used Vlieseline Style-Vil Sew In Foam for the cups (cut and sew foam is hard to come by in the UK) , which gave a clean, rounded silhouette and helped the upper edge stay smooth.
• The cup shape is ideal for a strapless: projection at the base, reduced volume at the top, and a secure neckline.
ELASTICS & FINISHING
• I used regular bra elastic for this version and it worked fine, but for the next one I’ll be adding silicone beading along the upper edge for extra grip and security.
SEWING EXPERIENCE
• Construction is straightforward if you’re comfortable with foam cups and elastic application.
• The cup seams nest nicely and press well over a ham.
• Rigilene boning is easy to work with. I trimmed the corners and melted with a lighter to smooth off. I also applied a small amount of Kinesiology tape to the ends for the boning on the back band to give some extra protection to the power mesh.
HACK POTENTIAL
This pattern is a brilliant base for structural garments:
• Longline: extend the cradle, add more boning channels (Rigilene works but firmer boning will give a cleaner line), and widen the hook and eye.
• Bustier top: lengthen to the waist, stabilise the front panel, and treat the back as a full fabric piece instead of a standard bra band.
INSTRUCTIONS
I loved the You Tube sew-along, I prefer this to written instructions personally, but the instructions are very thorougher
SUMMARY
Highly recommend. Great fit, great support, and a very hackable base pattern. I’ll definitely be making more — including a longline and a bustier version.
This is my first underwire bra that I've attempted and wow is it a great pattern. The video tutorial is thorough and very helpful. I have only completed my first toile, but man is it beautiful and supportive. With some small additional tweaks, I will have an amazing bra!
This is the first cashmerette pattern I have made. I found the directions to be very clear. Excellent detail. I am making this pattern for the inner bra for a wedding dress. I am really confident thos is going to stand and deliver. Thank you.
A lot of thought (and work) has gone into the creation of this amazing bra so full marks to Cashmerette! I did have some difficulty in gathering all the necessary components in the uk which has happened before when trying to purchase similar for bra making. However I did find that being ‘creative’ and swapping some for similar or making my own worked well enough albeit adds to the timescale process and could put some sewers off. I am very pleased with my own bra even though I don’t wear strapless tops but I do have off shoulder tops/dresses which I can now wear!
I didn't really need a strapless bra but the other Cashmerette bras fit me so well and I absolutely love a challenge. This went together smoothly. I referred to the sewalong video quite frequently for help. It fits great and is so supportive. It's really quite remarkable. I'll admit to being skeptical of all the boning, but I'm a convert. So now I need you all to come out with some dresses that need a strapless bra :)