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The Difference Between a Full and Partial Band Bra + How To Convert


I’ve sewn mostly full band bras, but I’m currently experimenting with a partial band style. The project has me going back to two posts I wrote about the difference between a partial band and a full band bra. I’ve learned a lot since, and there are some updates I’d like to make to that post. First is a clearer graphic that will hopefully explain the difference a little better. The measurements were also incorrect. I have deleted old posts since the information was not right and I’m fixing now.

And don’t think that I’m moving away from soft bras like Nina Warner! They are still my favorite silhouette and I see myself going that route in the future, but this partial brand is just a fun little project.

The pattern for a partial band and a full band bra are not the same, meaning you cannot sew the cups from a partial band bra into the frame of a full band bra. You also can’t decide mid-sewing to change a partial band bra to a full band bra or vice versa. In both cases, a pattern alteration is necessary. The only pattern piece that is interchangeable are the straps, and that’s assuming you have fabric straps and not elastic straps (elastic straps don’t require a pattern piece).

A full band bra is a bra in which the cups are sewn into a frame, and a partial band bra is a bra in which there is no frame and the band and the bridge are separate pieces. For both styles, the wire line sits at the base of the breast, which is indicated by the lighter blue line in the figure above, but the position of the cup seam is different depending on the style. Briefly put, the cups for a partial band bra are bigger than the cups for a full band bra to account for the channeling being flipped inside rather than outside. To understand this better, let’s walk through the construction process of each. On a partial band bra, the cup seam allowances, which are usually ¼”, are stitched to channeling, which is usually 3/8” (edge to edge, not the internal width). After the channeling has been attached, it is flipped to the INSIDE of the cup and stitched a second time. On a full band bra, the seam allowances, which are the same width as in a partial band, are also stitched to 3/8” wide channeling. After the channeling has been sewn, it is then flipped OUTSIDE of the cup and stitched a second time. Here’s another way of saying it – a partial band has an extra 3/8” built into the pattern to account for the channeling being flipped to the inside of the cup.

So, how do you convert a full band bra to a partial band? Let me show you!

Before I go into it, let me note that I’m using Beverly Johnson’s method from her new Craftsy class, Sewing Bras: Designer Techniques. Fabulous class!


The first step is to add the width of the channeling, which is 3/8″, to the cup seam line of the upper and the lower cup. Make sure that your channeling is 3/8″. In some cases, it could be 1/4″ or 5/16″ and if it is, add that measurement. Also, pay extra attention that you don’t add to the cross cup seam!

Next, eliminate 1/4″ from the cup seam line on the bridge.

After, draw the new bridge shape. I made the pattern into one piece rather than on the fold to make cutting easy. I curved the pattern slightly upwards at center front.

Connect the frame and the back band at the side seam so that they become one pattern piece instead of two. Then, draw the new back band piece. I placed the bottom of the band – where it meets the cups – 1/4″ lower than where the bridge meets the cup for a more flattering look.

That’s it! Well, you might have one more step – to add seam allowances – but I don’t to make pattern alterations quicker and easier.

So, why make a partial band bra? There are several reasons, but two main ones are that even though the cups are bigger, the total fabric yardage used is less. Also, because there is no frame under the cups, the band won’t roll up.

So, what does this look like in real life? Below, the white pattern is the pattern for Amber Rosalind, and in blue is the pattern for a new partial band, which I’m currently making. See how the cups are slightly bigger, especially the lower cup?

Have you ever converted a full band bra to a partial band? What was your experience?



  1. Reply


    Great post, Maddie! You’ve made it so clear! As a suggestion, in the Conversion image I’d include a note saying that seam allowances should be removed before making the adjustments (btw, I loved the way Beverly marked them with her pink sharpie!). You say it later in the post, but just in case…
    I’m looking forward to try this conversion, as well as the other techniques Beverly teaches in the class! But first I have to accomplish my self-imposed challenge of drafting myself a fitting full band bra… That little bastard is tricky! In the meantime I give myself comfort drafting bralettes… *sigh*

    • Reply

      Natasha Estrada

      I don’t think you need to remove the seam allowances for two reason. One in the cup you have to add 3/8″ all around so it makes no sense to remove the 1/4″ seam allowance only to have to add it again. If you remove it from the band/bridge there’s no point since your marking the new seamline up much higher and based on where the wire starts to go vertical so even finding the original seamline is not necessary. I always say don’t make more steps if you don’t have to. First pattern should be rough and dirty. It’s not going to be perfect so fail fast.

    • Reply


      Thanks for the suggestion Sofia! Great call out that I didn’t consider before posting. I always make my patterns without seam allowances and I forget that other sewers might do it differently! I see your reasoning, but I’ve decided the graphic is okay as is for the reason Natasha stated. You can remove seam allowances, but you don’t have to. It’s less work if you don’t.

      A full band bra is a tricky little bastard! Feel free to email me as you refine the fit. Happy to answer any questions you may have.

  2. Reply

    Michelle E

    Thank you! Pinning this now. I just bought the Craftsy class this morning as well. Now I just need to get some fabric kits and trimmings and I’m set to go! Wish me luck!

    • Reply


      Good luck!

  3. Reply


    Fantastic! It has so many great tips, tricks and overall clothing manufacturer knowledge.

  4. Reply


    This post just blew my mind. Thank you so much! I have to go try it out RIGHT NOW.

    • Reply


      Be sure to let me know how it goes!

  5. Reply


    Maddie, I’m so confused by this whole frameless thing I might cry!
    Why do you remove 1/4″ from the cup seam line on the bridge? In the pic it says to remove it because it is the width of the seam allowance, but then you say you work without seam allowances.
    And Beverly makes it even more confusing. I’m good at maths but I guess that manipulating patterns with seam allowances (in her Craftsy class) makes me so angry that I can’t focus and work it out on my SA-free pattern.

    Another question: how do you sew your channeling onto a full band bra exactly? I’m confused by this part “the seam allowances(…) are also stitched to 3/8” wide channeling. After the channeling has been sewn, it is then flipped OUTSIDE of the cup and stitched a second time.”
    What I do, is sew the channeling onto the band along the cup seam line. But I just simply cover the seam allowance with the channeling, like they do in RTW only I don’t have a double-needle machine, so go around twice. But there’s no flipping involved. How do you do it?

    • Reply


      Every sewer works with their patterns differently. Some alter with seam allowances and some alter without seam allowances. Regardless, the change from a partial band to a full band is the same – because you add to the wire seam line on the cup, you remove from the wire seam line on the bridge. I wouldn’t worry too much about removing from the wire seam line on the bridge because you’re going to eliminate most of it anyways. If you look at the illustration above – the only portion of the band that is kept is where the cups go vertical on sides. So let’s just say you don’t remove the SA – the band will be slightly loose and the bridge width too wide. You’ll notice it. First patterns are rough and dirty anyways, and it’s an easy pattern change to remove 1/4″ from such a small area.

      As for sewing the channeling, below is a link to Amy’s sew-along. For the most part I follow her method. Let me know if that gives a clear visual.


      • Reply


        I know 🙂 I wouldn’t dare interfere with anyone’s private (or even professional) methods. But I do have some background in teaching and find it frustrating when things are made any more complicated than necessary (which leaving the SA in does in my opinion) while imparting knowledge. But then despite the fact that I’m currently sewing at home on a domestic machine, I have a manufacturing approach and it’s a thing that’s usually frowned upon in the industry. At least from what I’ve experienced so far.
        My problem, nevermind.

        Yes, I know I can just manipulate the pattern later, it’s just I wanted to get the logic behind one aspect of it. But now I’m thinking there are more pattern drafting base rules around the world than I assumed and a thing I’m obsessing over might be completely overlooked by other pattern makers. I’ll figure it out.

        Thanks for the link! That’s an interesting method. Adds extra steps, but allows for accurate channeling attachment, esp. for a beginner. Will have to try it out.

        Thanks for the reply!

        • Reply


          A follow-up: Just used the flipping method 😉 of attaching the channeling. It works wonders! So glad that my little partial-band meltdown resulted in learning that method. Many thanks for pointing me in that direction!

          • maddie

            Awesome! Thanks for the update!

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