Something a little different from me for this post. I wanted to discuss that perennial old favourite – the full bust adjustment (or FBA) for a minute or two and I would love your input on my burning question (ooh what could it be? what could it be? I hear you all mutter excitedly to yourselves), which is about how you pick your pattern size.
Before I go any further, I want to qualify all the following with the fact that yes, I know that there is no 100% correct answer and everyone, ultimately, is decidedly different and unique and special (like, literally different, apart from exact identical twins and/or clones) and so whichever answer I pick, I know I will always have to make some adjustments anyway, so, you know, why am I even bothering to pin this down?
But the thing is, this has been bothering me and I’m one of those people that likes all the jigsaw puzzle pieces to fit. That is basically the reason.
Alright, so here’s the thing. I am a D cup in pattern sizes. That is, I have a high bust of 40 inches and a full bust of 44 inches – the conventional wisdom being that 4 inches difference = D cup. Most patterns are drafted for a B cup and this is really what I’m discussing here. There are certainly patterns with multiple cup sizes (woohoo!) and also patterns drafted for a larger cup (woohoo! x 2), but the industry standard is a B cup.
The advice you often get if you are a D cup-boobed lady, trying to fit a B cup pattern is to “pick the bust size based on your high bust measurement, not your full bust” and this is what I often do. I do have smaller shoulders/frame than my D cup boobs, so this does give me a better fit through the shoulders and armhole and then I do a full bust adjustment and grade out at the waist and hips, if necessary. This method definitely gives me a better fit than picking the pattern by my full bust measurement. Nevertheless, this suggestion does not totally make sense to me.
Why not? Well, because the numbers don’t add up. Yes, I am a numbers gal and it bugs the life out of me and I spend much more time than I ought to, staring at numbers and tutting to myself and trying to work it out. I really wanted to start a little mini-project and experiment with several types of full bust adjustment on the same top (Inari tee by Named if you were wondering), but I decided that before I could do that I needed to once and for all sort out my dilemma until I was happy and satisfied. So here we are.
Let me show you what I mean. I picked this pattern table because it has some good numbers.
In the chart above, if I picked by my full bust size, I would make the 18, with a finished garment size of 46.5 inches. I know, however, that the fit around the shoulders and armhole would be too big. Many, many companies (and advice on the internet) tell you to use your high bust measurement. Mine is 40 inches, so I would therefore pick the 14. Now, often, the same instructions tell you to make a one inch FBA on your pattern piece for a D cup adjustment, which is a total of 2 inches (two boobs). This is explained (in several different ways, but ultimately the following) as the “difference between a B cup and D cup is 2 inches”. Can you see the problem though?
If I take the 40.5 inches here and add 2 inches in total (with a one inch FBA), my finished garment size is only 45 inches in circumference. That is, it’s the finished garment size for the size 14 of 43 inches, plus the added 2 inches from the adjustment. My bust is 44 inches around, which only gives 1 inch of ease – a fairly tight fit – and certainly not the 2.5 inches of ease if I’d used the size 18. So where did that extra 1.5 inches go? It drives me nuts I tell ya. Every time I think I’ve sorted the FBA issue in my head, it pops up again in a new pattern when I’m reading the instructions. I can tell you that I’ve done a LOT of internet searching to check I wasn’t missing something obvious or going crazy.
And here’s the thing: what a few pattern companies tell you to do (but only a few that I’ve seen) and also what I also found in some of my fitting books and in a Craftsy class is not to use the straight high bust measurement. You use the high bust measurement PLUS 2 inches. That is, if you know the company drafts for a B cup you use 2 inches. If it were a C cup, you would use the high bust measurement plus 3 inches, and so on.
In the example above, I would use 40 inches (my HB measurement) plus 2 inches = 42 inches. I would therefore select the size 16 instead and do my 1 inch FBA. The finished garment size of the 16 is 44.5 inches + 2 inch FBA = 46.5 inches! Hooray! The exact same measurement as if I’d used the full bust adjustment, but with different proportions. This makes SO MUCH MORE sense to me. Another way to think of it is: if there were another set of measurements showing the high bust measurements, what would they be? Well, they would be the full bust measurement minus 2 inches, so I would see very quickly that my 40 inch high bust measurement would appear under the size 16 and would immediately choose that size to make. Logical, isn’t it? Is it just me?
Big 4 pattern ease?
This leads me to ask then: why do many companies say just to use the straight high bust measurement? I also saw it a lot in pattern forums from sewists who sounded like they had a ton of experience/knowledge. Now, in these places, it was mostly the Big 4 patterns that were being discussed, which led me to wonder if that was an issue. I think we’ve all experienced the rather large amount of ease in Big 4 patterns. At least, I have, and have had to size down numerous sizes. So I guess I’m wondering if for the Big 4 patterns, getting more brutal with your downsizing is necessary to get a good shoulder and armhole fit? I saw one sewist say “oh no, I had to go down from a 16 to an 8 to get a good shoulder/armscye fit and that’s not unusual”. That does really seem like some excess ease then!
Perhaps that’s why some of the books that are teaching tissue fitting use this too? Most tissue fitting is done with Big 4 patterns. Plus, once you get the shoulders right, you can slash the pattern to get your required extra bust room and not worry about working it out with a ruler and pencil. It’s only a guess.
Indie patterns adjustments
My understanding, and I hold my hands up – it is a generalisation – is that many indie pattern are designed with less ease than Big 4 patterns. I suspect potentially both wearing ease and design ease, but of course it varies with the company. And so perhaps that explains why on some indie patterns, I’ve made the suggested adjustment using the straight high bust measurement, but it seems a tad pinched in some areas. One crucial factor seems to be this advice to use just the one-inch increase – I don’t think it’s enough.
Of course, if I use the smaller size I can just make a bigger FBA adjustment instead and, in fact, that is what I inadvertently started doing for a few patterns. On some occasions, there were no clear instructions, so I started adding FBA inches that were bringing me up to the same finished garment measurements as the full bust measurement column. However, it meant I was starting to do minimum 2-2.5 inch FBAs on a smaller size, which also meant adding quite a bit of width to the bodice. In a few cases I felt it was slightly starting to warp or fundamentally change the design draft.
Most recently, I did a 2 inch FBA on a princess-seamed pattern and the piece looked rather odd. I’ve since discovered advice that once you get past 1.5 to 2 inches, it’s advised to switch to a different method that doesn’t add more width (at least that’s what it says in some of my fitting resources, but they are, obviously, all completely bleedin’ different as well, heh), but that’s a whole other discussion.
Now, the main issue with all this musing is that unless I try it out I won’t really know the answer. Which means making a lot of muslins! And… that’s a lot of work. It’s also entirely possible that I will make the high bust + 2 inch muslin and it will be too broad in the shoulders still! But I wonder if that would simply mean I actually need a narrow shoulder adjustment at that point and that I am, nevertheless, still muslining the bodice with the correct intended proportions for that garment with regards to the bust – shoulder ratio.
In the meantime: what do you think? In case I’ve lost you with my ramblings, the burning question is:
Should you pick a size based on your high bust measurement or your high bust measurement plus 2 inches? (assuming B cup drafting and a D cup bust)
Is this something that has kept you awake at night too? Is there a good reason I’m missing for any of this? Is it all rather obvious? If you agree with me, then why is it explained like this? Does it even matter? I can ask a lot of questions in one paragraph, can’t I? I will probably try and find answers by concurrently asking in some forum or other, but the only time I saw this exact question being asked, it seemed like the questioner wasn’t understood at all. I could see her getting frustrated repeating herself, and if it hadn’t been back in 2014 or something, I would have jumped in. She could have stopped sewing in frustration by now for all I know. Wouldn’t blame her actually. Joke.
To reiterate what I said at the top, ultimately we all have to make personal adjustments anyway, so I do view this as just a starting point. But I like my starting points to be logical, and then move from there, goddarnit! I would be quite happy to have a rule-of-thumb: eg. Big 4 patterns use HB measurement; indie patterns use HB + 2″ as a starting point. I’m asking because I genuinely do appreciate any insights. If nothing else, I find it all rather random and interesting, which my husband decidedly doesn’t and which led to me writing this as his eyes glazed over for the 546th time as I tried to explain it to him.
Ciao for now! xx