I bought the Boylston bra pattern by Orange Lingerie a few months ago. I had briefly (!) dabbled in bra-making with a couple of Kwik-sew 3300 bras (below), which were good, but I was keen to make a foam cup bra.
Then I found a bag full of bra-making supplies at the op shop. Score of the century! I could wait no longer and got cracking on the Boylston.
Notes on Boylston sizing for anyone interested
I measured myself carefully, studied the size chart and decided I was a 34C. This ended up being very wrong and way too small and I will explain why for anyone contemplating this pattern (I would be interested to hear how the sizing worked for others).
For the band size, the instructions have you take your underbust measurement in inches then add 4 or 5 inches depending on whether it was an even or odd number, respectively. This gave me 34, but the 36 was actually the right size band for me.
For the cup size, you need to find the difference, in inches, between the high bust and full bust measurements. My difference was 2.5 inches, which put me between a B and C cup. As instructed I rounded up to a C. After making two C cup bras, I eventually decided I was a D cup in this pattern.
The fitting of the three bras I made was as follows:
34C - way too small to put on and do up.
36C - comfortable and wearable, but the bridge sat away from my chest and the bra tended to ride up with wear. Thank you Mr Humphries (showing my age with that one!).
36D - very well fitting and comfortable with the bridge sitting against my chest. If I was being very picky I would have the top edge of the cup pulled in slightly.
So, my experience was to go up a full band and cup size from what was indicated in the size chart. This meant going from 34C to 36D. My RTW bra size is generally 36D.
The foam I used was 3mm thick. I removed the seam allowances from the foam pieces, so they were stitched with no overlap. Use of foam and its thickness may influence sizing.
I made my first bra, the 34C, from this pretty Potter's Textiles remnant and used some foam I found at Remida for the cups. The back was made from power mesh. I'm so upset this was too small.
And here it is on me. Now I have the sizing worked out, I'm really happy with this pattern and will certainly be making many more.