Navigating the minefield

I mentioned before just how problemetic bra sizing and bra shapes can be, didn't I? And guess what? That first bra I made, the one I was kind of happy about? When I was wearing it last week, my suspision that the cups were too small returned again. Although my breasts filled the cups fairly well (a tiny bit of bulging over the front edge), the wires seemed to sit on the sides of my breasts, rather than around them. I showed the bra to M (after all, she got me started at making lingerie and she knows this stuff) who not only confirmed my misgivings but also pointed out that the center front bit, the bridge of the bra, was too wide as well, causing the wires to sit on my breasts at the center too.
According to her, that would put my size as 'BB', the volume of a B cup but with a different width (just for the record, the 75B of my usual brand of RTW bras fit  just fine...) 
Talking about this, we concluded that, as in outerwear, underwear manufacturers all design their product with a specific target audience in mind. Although there is sort of a rule about bra sizing, shapes and sizes and elastics can vary wildly from one brand to the other. Which is why help with fitting can be so important (there is some statistic going around according too which half of all women wear the wrong bra size...) 

The 'rule' from bra-sizing is based only on the difference between one's underbust measurement and bust measurement. This doesn't take into account breast shape, torso shape or the way the breasts are placed on the torso. For all those things, those of us who buy bras have to rely on finding the right brand and those of us who sew them have to make muslins and tweak our patterns.
And the rule isn't set in stone either. The cup size chart from Pattern School is here and that one fits in with my personal experience. However, according to both my lingerie drafting books, a difference of 12-14 cm is for an A cup (and 14-16 cm=B, 16-18=C, 18-20=D, according to the Ann Haggar book).

The right shape bra is as important as the right size. 
If the wire sits on the side of your breast, it will, over time, push that flesh to the side, under your armpit (of course, this is only if you always wear the wrong size and shape bra). If a bra fits well, the wire should fit around the breast. This can be a problem, especially for those who have wider torsos and smaller breasts. In RTW, the only option in that case is usually to stuff the cups... when sewing, go for the needed wire size and alter the cup pattern pieces, making the end result a bit more flat. 

In theory, I knew all of this but dealing with it myself proved to be a different matter.
Not to be subdued, I decided to pass by the habedashery store on my way home and pick up a pair of cup B underwires (the ones I used before had come from my stash of wires-from-old-bras. I have had the habit of salvaging the wires from old bras ever since I followed M's lingerie making workshop years ago. And all my old bras were from back when I had cup A). 
And guess what?

These are all the different bra wires I have. In theory, I would expect the normal wire for sale to be the an almost perfect semi-circle, intended for a full cup bra (many of the normal styles in RTW are technically 'half cup' bras) with a set wire length for each cup size. Sigrid just posted about that shape here.
In this picture, you can easily make out the wire I bought because it's the only fully painted one: the white one, third from the top. 
You may notice that it does, indeed have that semi-circular shape. You may also notice that it's the third smallest wire in the row... And this case, I was careful not to let perspective influence the image. 
This Prym brand cup B underwire is smaller than most of the wires from my old cup A bras. Even though a lot of the larger ones came from foam cup bras, I didn't quite expect this. I did learn my lesson. I'll only ever buy wires by exact length from now on. Cup size is just too tricky (oh, and you do know of course that cup sizes only exist in relation to band sizes? The wire size for an 80B is the same as that of a 75C, a 70D, an 85A and a 90AA... I would expect notion brands to use either 75 or 80 as the standard on which to base their sizing).
The long, deeply curved wire on the bottom is one I am using now for new bra. To get it, I bought a the cheapest 75C bra at Zeeman (a Dutch chain of  bargain clothing stores). It cost me half a euro less than the Prym wire and of course, I checked the measurement before buying. I worried a little about the deep curve. My pattern looked more wide than deep to me but I decided to give it a go.

I have some more observations about wire shapes for bra styles, but those will have to wait, this post is getting long enough as it is.
I will show you some of my bra drafting stuff though.

In Een Tweede Huid the basic draft for the cup has vertical seam. I did my alterations to that first and tested it. Both pieces ended up a little wider than before and I tweaked the balance between the front and side (because the front top edge cut into my breast a tiny bit, while the side top edge was a gaping a little). After that, I drafted cups with a horizontal and a diagonal seam based on that well-fitted vertical one.

This is the pattern I made for my new bra. Diagonally seamed cups, small separate center front piece, sides which are shaped at the point where the shoulder straps will be attached. The pattern pieces are including seam allowance.
I've been sewing on it already and I have good hopes for this one. 

P.S. some people mentioned wanting to copy my idea for lace back panties. Of course everyone is welcome to do so. I will post some notes later this week about what kind of pattern to use and how to cut and alter it.