The Flynn jacket is intended to have a substantial amount of design ease, to create an oversized shape, designed for layering. For this reason, I suggest focusing on your high bust measurement when selecting your size. The size chart for the Flynn jacket can be found here.
This pattern is drafted for a B cup bust. Due to the large amount of ease, it is unlikely you will need to do a full bust adjustment (or small bust adjustment) for View A. Check the finished garment measurements to ensure it will fit through the waist and hip.
For View B, which is closer fitting, due to its sleeveless nature, you may consider this alteration to achieve a better fit through the shoulders and armhole (and also so you can close it, if you would like to add a hook and eye). For today’s post, I will get you started for doing the adjustment and then will link to a past post that I wrote about full bust adjustments.
WHEN YOU'LL NEED TO DO A FULL BUST ADJUSTMENT
Most indie pattern companies (including In the Folds) draft for a B cup bust. There are of course exceptions to this rule (such as Cashmerette and Colette Patterns), so make sure you check on your pattern before assuming the bust cup size.
In terms of the Flynn jacket, it is a loose style which means it is a little more forgiving than more fitted patterns (such as the Acton, for example) so in some cases you can probably get away with not making a bust adjustment. For example, if your bust is smaller than a B cup, it is unlikely you need to bother doing a Small Bust Adjustment. I have an A cup bust, but have not made adjustments to any of my Flynn jackets. Also if your bust is just slightly bigger than a B cup, it is also likely you will be okay without the adjustment.
Check the finished garment measurements and go from there.
WORK OUT YOUR CUP SIZE
Your cup size in sewing patterns may not always correspond to the bra size you wear. To be safe, check your measurements before deciding if you need to make any adjustments to the pattern.
To do this, measure your high bust measurement (the area above your breasts, under your arms) as well as your full bust (the fullest part of your chest) and then take note of each measurement, as well as the difference.
If the difference is 2.5cm (1") your bust is an A cup, 5cm (2") it's a B cup, 7.5cm (3") is a C cup and so on.
CHOOSE YOUR SIZE
Now, go back to your high bust measurement and add 5cm (2"). This is what your bust measurement would be if you were a B cup and therefore the size you should be choosing from the pattern.
For example, let's say your upper bust measures 81cm (32"). Add 5cm (2") to this measurement to find out what size your bust measurement falls into on the In the Folds sizing chart (and what size you would be if you had B cup breasts). 81cm + 5cm = 86cm which corresponds to a size C. Your actual bust measurement is 89cm though - 3cm (1") larger than the cup size of the pattern. This means you need to do a FBA and add this 3cm (1") to your pattern.
As the front pieces are cut as a pair, you need to take the measurement you will be adding and divide it by two. For example, this 3cm (just over 1") mentioned in the example, will be split between either side of the front - 1.5cm (1/2") on each side.
For the sake of the example, I will be making the adjustment to the pieces of View B (as this is the style most likely to require the adjustment), but you can follow this tutorial for View A too.
Take the two pieces that make the front of the Flynn jacket - the FRONT HEM FACING  and the FRONT . The first step will be to turn these pieces into one pattern piece (removing the panel line) as this will make the adjustment much easier to manage. At the end, we'll put the panel line back in place, so there won't be any change to the design (except for the addition of the dart - which can be removed later on, if you prefer).
A - Take the SIDE FRONT  piece and place it on top of the FRONT HEM FACING , lining up the stitch lines (the grey line on the pattern), as if the pieces have been sewn together. If you are struggling to see the lines, it can help to put the pieces up to a window and see through the paper that way (or a lightbox, if you have one). Once the pieces are correctly lined up, use masking tape (or similar) to hold the pieces in place.
As you can see in the example, you won’t be able to align the stitch line for whole seam, as the lines slightly change directions towards the shoulder (which is what gives you a nice shape in that area). Just focus on lining up the stitch line in the lower section of the pattern (as illustrated).
B - Take a piece of pattern paper and trace the piece - being sure to include all pattern markings (in this case: the grainline and notches). Also trace the panel line.
Make sure you trace both the cutting line and the stitching line - this is really important. In the Folds patterns include the stitching line on each pattern piece so that it is easier for you to make alterations to your pattern. I know we would all love to be able to cut a pattern in a straight size and for it to fit perfectly, but unfortunately that's not the way it is (I even have to make adjustments to In the Folds patterns so they fit my figure properly), so having the stitch lines can help you make adjustments more quickly and easily. When making pattern alterations, I normally suggest removing the seam allowance, but because the stitch line is marked on the pattern, you can leave it on.
From this point you are ready to make the adjustment. Head over to this tutorial - starting at STEP 3 and work through the tutorial.