Designing a graded pattern for an “FBA” or Full Bust Adjustment – Warning: This is Technical – Part 3
Are you back for more information? Perfect. Let’s get started.
For the Rachel Tank, I didn’t want to account for any stretch. I’m kind of tired of my knit clothes being so tight that my body rolls show through. I like knits because there aren’t zippers and can be pulled on easily. I wanted a tank that I could wear to the gym or around the house and feel comfortable in it.
I could technically have removed the ease I accounted for in the hips and waist since I didn’t add any ease in the bust. I figured that the bust didn’t need any additional ease. I will likely do a more fitted tank around the waist and hips, but on another design.
The beauty about knowing grading and pattern making, I can make a minor change and I have a completely different fit.
Step 4: The Actual Grade
I draft and grade using a software called PolyPattern. Shown below is the pattern I started with from the original Porcelynne collection. The patterns to the far right were the original patterns. The patterns on the left side are the patterns that were adjusted for the waist and hip measurements. The far left is without ease and the one to the right of that is with ease.
I graded the back according to the back grade chart. (Sorry, no specifics here – That is a different topic for a different day.) I took the front and added a dart for a better fitting A/B cup size. I also marked where the apex was so I knew how far the dart ended from the apex. For the A/B cup, I believe I had it end about 1 1/2″ away.
Grading the bust sizes proved to be complicated as usual. When is anything cut and dry in life?
I first graded the dart for the increase in bust size. The measurement across the chest increased by 1″ for half the front, so not only did I have to increase the width of the body at the bust by 1″, I also had to make the dart wider by 1″ to better shape the larger bust.
That was the easy part. The hard part was the side seam and armhole lengths. In the screenshot above, I included the measurements for the side seam.
The side seam was the part I tackled first. As you can see, it was virtually impossible to keep the waist measurement the same and have the pattern look presentable. I was able to keep the hip, but I had to increase the length a bit to keep the side seam measurements the same.
I determined the side seam of the back, so adjusted the side seam at the hem and underarm to make the measurement match. I had to do this by making tiny changes to the grade under the arm and at the hem. I used the define measurements tool on PolyPattern and plugged those into one of my handy spreadsheets.
Step 5: Fitting and Adjustments
What I originally forgot to do was to take measurements on the armhole for each size. When I first released the Rachel Tank, I didn’t realize that was an issue at all. One of my customers showed me her top and the armhole wasn’t right. Here she showed it to me. She didn’t think it was that big of a deal, but I did. I immediately went back to the software and re-evaluated the armhole size and shape.
I noticed from this first picture that this size needs to have the armhole lowered by about 1/2″, but she never mentioned that.
This picture made me realize I did not shape the armhole correctly. I have since gone back in and shaved off a good inch in the front armhole in this size. Fixing this one size, helped me determine the changes needed for all sizes.
I also realized the back armhole needed a little reshaping in the lower portion. The wrinkles tell me that. I shaped off about 1/2″ on the XL, 2X and 3X.
In the original Rachel, my armhole shape got smaller as the bust size went up, which should not happen at all. When I fixed the armhole grade, the first 3 cup sizes were about the same armhole measurement and the last 2 sizes increased. I had originally wanted them to all increase, but I was unable to get the second 2 sizes to increase in length with a shape that looked right. I figure it is what it is.
There you go. That’s my saga. There is a lot of technical stuff that goes into grading. I promise I’ll write a post on altering the bust size by hand for one bust size.
I think it is possible to infer how to do that with what I did here, but then again, I am all about the math and it is complicated.
Designing a graded pattern for an “FBA” or Full Bust Adjustment – Warning: This is Technical – Part 2
How is your brain capacity for grading right now? Overwhelmed yet? I wanted to break the bust grade out into a new post because its is more complicated.
Step 3: Bust and Across Back Grades
To better understand the relationship for a bust grade is different than a size grade. Looking at the quick graphic below, size grades go from one full body size to the next. The cup sizes for rtw are unrelated to the body size. For the cup size grades, you need to keep the waist and hip measurements the same for the same letter size, but the bust size changes.
I pulled my largest measurement for the cup range from my previously defined charts and dropped it into this chart.
The bust area is a tricky task to deal with. I next had to define my bust span for each size. This is the measurement from apex to apex. This part was a lot of work, so I’m not going to share this chart with you. (I know, I’m mean.) I will add this to the book I write on the subject, but at this point, I’m not going to share it. (I know, I keep saying this and it is still mean.) This part came from a lot of trial and error. I took what I knew about bra making, but also incorporating ready to wear bust spans into the mix.
For a quick reference, here is the full size chart again that I explained in the first part of this article.
My next task was to determine the across back measurement, which is the amount from armhole to armhole. I use the underbust measurement (from my sports bra chart).
In the case of the XS, the underbust was 27 on the larger side of the range. The back for each letter size is not graded for the bust, so we need to determine the back sizes before we can determine the front bust measurements. I took the 27 and divided it by 4. The quarter measurement for the XS is 6.75. These amounts are for the back of each size.
For the front, we remove the across back from the full bust measurement. This is determined by taking half the underbust measurement and subtracting it from the full bust. For the XS – A/B Cup, this leaves us with 16.5 or the half amount of 8.25.
The grade amount for each bust size going down the chart is a total of 2″ for the full grade. Each bust size is indicate by a 1″ change of circumference. This amount covers 1/4 of the body, so the grade amount shown is 1″.
Have I lost you yet?
We haven’t even gotten to actually grading yet. There is a reason it takes pattern makers years of schooling and practice to get this right.
I’m thinking I need to end this post here and let it simmer in your brain. The next and final post will be how I did the actual bust adjustments on the pattern.
Designing a graded pattern for an “FBA” or Full Bust Adjustment – Warning: This is Technical – Part 1
I recently created a pattern called the Rachel Tank, with 5 bust size options. It was a challenge to determine how to break down the sizes. I wanted to create a versatile pattern, but really didn’t want to have to create a different pattern piece for every bust size known to man.
I chose this simple design to help me establish my grading for bust sizes in RTW styles. I know grading extensively for bra making and for basic patterns, but I never tried adjusting a pattern for a full bust. This series is on how I altered a basic tank with a “FBA” or full bust adjustment. I don’t go into the nitty gritty of making changes, but this series tackles how I created my grade rules for the FBA on a RTW garment style.
I first took a basic tank from my Porcelynne collection from years past. It is a simple tank I made thousands of times over the years. It was great for me when I was on the thinner side. I might have been a DD when I was a size 10/12 in the past.
I am now a I/J cup and a size 18, although I am slowly losing weight. I laughably tried on one of my tanks from my younger days and thought – well, this won’t do. I need to create something for “real” women, aka myself.
I spent several hours redesigning my basic Porcelynne tank to include a dart – which makes it shaped better on the body. I also removed some of the fitted-ness of the top. I figure it is always easier to remove, than add, once it is sewn together. For someone who wants a more fitted tank, the individual can take it in on their own.
I had already spent hours (but closer to days) developing the size chart of my Christina Sports Bra. I planned this to be the base of all my sizing. I will try to walk you through my grading madness.
I have a spreadsheet with multiple tabs going. Some accounting for stretch on a garment and some for non-stretch. I probably won’t share all of it, as it was a lot of work on my part and honestly I am always adding to it when working on a new garment. (This is a foreshadowing that I will be writing a book on grading- but not today!)
Step 1: The Size Chart
When making the grade, I first needed to create my size chart, aka my grade rules. I used my existing sizing from the Christina Sports Bra. This is only for part of my size chart – 28 through 40 Bands (the rest of the chart can be seen on the Christina Sport Bra product listing). The cup amounts are the full bust measurements.
I took this size chart and accommodated it for letter sizes, meaning small, medium, large, etc. I took the basic size measurements for the B cup for the A/B Cup sizes of each letter size. Letter sizes generally cover a range of number sizes. For example, a small covers dress sizes 2 and 4.
Not everyone has the same chart. Mine may not be appropriate for you to use. Mine is for my customer. I have already trained my customer with my previous patterns (California Dreaming and Christina Sports Bra). My existing customer knows how my patterns fit, so this size chart reinforces my existing fit.
I added the corresponding dress sizes, my sports bra band sizes for reference, waist, hip and my basic bust size of A/B. As you can see by just looking at the XS, the A/B cup size is my B cup for the 28.
Things got more complicated for the rest of the sizes. I had to make a call on how my sizes were created. I initially took the smallest A measurement for the smaller size and B measurement for the larger band size. For the small, that would be 31-34, which is a 4 inch range.
Letter sizes are traditionally a 4″ change in circumference from size to size (not including any stretch adjustments). To me the 4″ change for the bust size was too big of a change for each cup size.
I opted to make my bust size range only 3 inches instead of 4 for the A/B, but only 2″ for all other cup sizes. I played around a bit with my numbers and this is the chart I came up with.
My bust sizes don’t necessarily equate to the actual bust sizes from the sports bra size chart, but they are close.
Step 2: Measurements for Patterns
The size chart was the hardest part of all of this, but I can use this size chart for all my future patterns. It is important you have a sound size chart prior to developing any patterns.
The second step was to determine what measurements I was basing my patterns on for each size. You can’t have a range at this point, only a singular number for each point. I started with my waist and hip measurements since those were the simplest to create.
If you notice, the waist measurement I listed here is larger than the largest size in each range. This accounts for 2″ of ease in the garment. Remember, I have not adjusted the charts for stretch, so this chart is still being built for normal ready to wear. Some pattern companies may use the middle of the range and some may use the lower end of the range. These decisions are done by the designer and no choice is considered wrong. I prefer my patterns to be on the generous side, than “smaller than expected.”
In this chart I write in the full amount with ease, then break the amount into 4 since most drafting is done on one quarter of the body. I also list how much my grade is between each quarter amount. This shows my growth per size, or my grade per size.
Am I losing anyone yet?
I will stop here for the day. The bust grades are more complicated, so I’ll let this sink in for a day or two. Tell me what you think I might do for the bust grades. I’ll include the result in Part 2 of this post.
If you ever wonder why its so expensive to hire pattern makers or why pattern makers always ask for a defined size chart, hopefully this will help open your eyes to why we ask for it.