What is duoplex fabric?
Duoplex is a low-stretch knit fabric made of 100% polyester. Duoplex is a low-stretch fabric due to having very little mechanical give on the cross grain and no stretch lengthwise. It is a lightweight fabric with drape that compliments lingerie apparel.
This post contains affiliate links. When you click and make a purchase from these links, we might get a commission. It doesn’t cost you anything extra!
Duoplex also has great support and is used for bra cups and bra frames and bridges. When using this fabric for your bra cups, frame or bridge you do not need to line your fabric. This is a strong supportive fabric with little to no give making it ideal for bra making. Duoplex is typically reversible as well with one side matte and the other side shiny while still being soft to the touch. You can use either side as your main fabric. There are also sheer options available in addition to coming in a variety of colors.
Duoplex is also considered a tricot so be careful not to get confused when shopping for this fabric.
Characteristics of Duoplex
- 100% polyester
- Low-stretch
- Lightweight
- Nice drape
- Supportive
- Sheer options
- Typically reversible – matte/shiny
- Soft to the touch
- Comes in a variety of colors
- Great for lingerie apparel
- Perfect for bra making – specifically cups, frame, bridge
- No need to line this fabric when using it for bra cups, frame or bridge
- Considered a tricot
What is the purpose of duoplex?
Duoplex is strong supportive fabric with little mechanical stretch making it ideal for bra cup fabric. It is heavily used in lingerie including bra making and lingerie garments that require support with nice drape. Duoplex is ideal for bra making because it does not need a stabilizing fabric such as bra cup lining. Bra cups are designed to not have stretch in order to hold the breast in place and shape the breast tissue. You may decide to line your duoplex fabric mainly for comfort if your bra cup design has seams. These seams may rub against the breast tissue causing skin irritation. In this case, you would line your duoplex with the recommended bra lining fabrics or seam tape.
Why use duoplex for lingerie?
Duoplex is often used by beginner bra makers to get a hang of the process before adding the additional step of lining your bra. Duoplex is not only great for lining your bra cup but it is often used on the bra frame and bridge as well. These two areas also need to be rigid in structure to hold up the breast and allow the bra to lie comfortably against the body. Duoplex comes in a variety of colors so it is easy to add decorative elements to your fabric as you become more confident in bra making or lingerie design. Lace, ruffles and other design elements can be sewn onto your duoplex fabric. You can also find matching powernet or powermesh in the same color to create a bra and panty set. You may even add decorative elements to match your underwear as well.
Duoplex offers beginner and advanced sewists and everyone in between a variety of options in bra making and lingerie. It is highly recommended for beginning sewists in the bra making world to try their first bra with duoplex so you can build the skills necessary before your experiment with stretch fabrics, lining and decorative elements.
Best practices when sewing with duoplex
Duoplex is considered a knit fabric with little to no stretch. You will find mechanical give on the cross grain. When sewing with knits it is recommended that you use a ball-point machine needle and a 3 step zig-zag stitch on a standard home sewing machine. You can also use an overlock machine on side seams. Polyester thread is also highly recommended when sewing with knit fabrics, specifically for bra making and lingerie apparel. It is also recommended that you loosen the presser foot pressure slightly on your home sewing machine to avoid any unnecessary stretch while sewing that could warp your stitch or seam.
Here is more detail on best practices when sewing with duoplex:
- Best machine needle
- Best standard machine stitch
- Best thread
Machine Needles:
Your sewing machine should have come with a universal needle. It probably came with a few extra needles as well. Those extras may just be universal or they may be a different size. When starting out you can use a universal needle but eventually you should invest in a ball-point needle or stretch needle. This is a finer tip needle that doesn’t break the fibers. Rather the needle point separates the fibers which is important for maintaining strength when sewing a knit fabric.
Stitch Type:
- Zig-zag Stitch
- 3-Step Zig-zag Stitch
If you do not have an overlock machine the zig-zag and 3-step zig-zag stitch are right for you. This is a strong stitch in that essentially encases the raw edge of the fabric by wrapping the threads around the edge and locking them in place. The 3-step zig-zag takes the same form but it makes three straight stitches from one point to the next point of the zig zag. The 3 step zig-zag is stronger than the standard zig-zag which is preferable for lingerie since it allows the fabric to stretch while being worn.
Thread:
When it comes to bra making and lingerie sewing a polyester thread is highly recommended. Polyester thread is stronger than cotton. Cotton is likely to break as it cannot withstand the stretch necessary for bras and other lingerie. Stretch is a vital feature in all lingerie whether that be with your fabric or notions. Thread is no exception. My favorite brand it Gutermann which can find at several retailers.
Care Instructions
Always be cognizant of the care instructions provided by the retailer for your specific fabric. I am not responsible for fabric that has been damaged while laundered under your care. These are general instructions and will not apply to all fabrics.
These instructions are based on duoplex that has been used for lingerie garments such as bras.
To increase the lifespan of your bra it is always recommended that you hand wash your garments using a gentle detergent of your choice. Follow the instructions of your detergent for proper usage.
If you are not sure how to hand wash your duoplex bra then use a small amount of detergent and lukewarm water allowing your garment to soak for about an hour. Gentle rub your garment if needed then rinse with cool water until the water runs clear. Lay your bra out on a towel to dry in order to avoid stretching the fibers then gentle push the water out with another towel on top. Remove the top towel and allow your bra to dry on a flat, dry surface.
Where can I find duoplex?
There are many great retailers carrying duoplex fabric. To make it easier on you check out my fabric recommendations on my Recommended Fabrics page to find your duoplex fabric today.
Conclusion
Duoplex is an ideal fabric for first time bra makers. It is a strong, durable knit fabric with little mechanical stretch. When using on bra cups, frame or bridge you do not need to line this fabric. You can add decorative elements to the outer fabric if you wish. Duoplex is soft to the touch and can be reversible from matte to shiny. Both sides can be used as the main outside fabric. Sheer duoplex is also available. Duoplex comes in a variety of colors as well. Duoplex is also recommended for lingerie garments that have drape because of its lightweight qualities. Hope you find many uses for duoplex fabric as you dive into the world of lingerie making!
Happy bra making!
