I mentioned in my Renfrew Top post that I used a vertical only FBA. A couple people asked me for more details. I use this sort of FBA routinely in knits, when I am making a top with negative ease. (You can read more about negative ease in my Uber Busty post.)
When you have a pattern where there is enough width in the pattern piece to go around the bust, you may still need a full bust adjustment (FBA). This is because you still need extra length in the front to go up and over the bust. Unless, that is, you like tugging at your front hem because your top constantly hikes up in front.
In this situation, I perform a vertical only FBA:
- Mark the bust point on the pattern tissue. (I never use the bust point marked on the pattern. I pin the front and back pattern tissue together at the shoulder seam and put it on my body. I line the CF up to my CF and mark the bust point with a pin/pen. My bust point is always lower and farther from CF than the pattern company indicates. This is why, by the way, I don't like patterns with the bust darts already drafted in – for me it's easier to add a bust dart than it is to move one.)
- Slice the front pattern piece horizontally at the level of the bust point.
- Add length evenly across the pattern piece. For my bust, I usually add 1" to 1.5", but YMMV (your mileage may vary). When you wear a RTW top, how much shorter is the top in front, due to your bust? That's about how much length you will want to add.
- I also curve the side seam out slightly at bust level - I may cut this off later.
Here is the resulting Renfrew pattern piece, to give you an idea of what I mean:
How I sew this up depends on the fabric. In a stretchy knit, I ease this extra fabric at the sewing machine. (I ease it in over a couple inches at the level of the bustline - I do not ease it in over the entire side seam.) Note that I do not gather the extra fabric – I do not like the result when it's gathered. I just stretch the seam so that the back (which is shorter) meets the front (which is longer) and stitch.
In a stable/beefier knit, particularly if it's a 2-way knit and there is no stretch in the up-and-down direction, I sew it up as a dart. But I don't sew the dart until the shoulder seams are sewn, then I put it on and pin the darts right on the body. I do not like to sew darts in a stretchy knit, which is why I ease the seam in such fabrics, but do what pleases you.
After I sew the darts, (and possibly the sleeves if they are being sewn in flat), I pin the side seams, try the top on, and check the fit. I then machine stitch. I never just sew the darts or the side seams without pin fitting and I often tweak the fit at this point. It's really worth taking the time and trouble to get the fit just right – the result is much more flattering.
By the way, with only a couple of exceptions, most of you didn't mind if I turned off anonymous commenting, so I did. It has been a blissfully quiet day on the spam front. Maybe, at some point, I can re-enable anonymous commenting, but this is a nice break.