I'm trying to figure out my correct size. Going by the intervention thread, I am a 34F. However, a 34F seems perfect around the back, really comfy, but I've noticed a slight bulge on the cups i.e they are slightly small. Went up to a 34FF, and everything is digging . Band seems tight, the 'end' of cups are digging, but the overall cup seems to fit right.
I'm a 34G so I feel your pain!! Firstly have you had a proper bra fitting in a good department store? Also if you have a Bravissimo near you, they are excellent. My experience is, it depends on both the make and the style as to what works as they are all slightly different. However, bras for bigger boobs have come a long way from what they used to be... Keep trying and good luck!!
I was measured by Bravissmo and was a 34E, however since then I've had two babies in 14 months , youngest is 10 months now. So by self measuring I appear to be a 34F. The F and FF were both the same t-shirt bras but a 34FF balcony bra felt better than the t-shirt one.
Sounds like some style issues, t shirt bras are actually quite difficult as they either fit, or they don't - they are quite a fixed shape so they don't mould themselves to your body the way a non moulded does. It could be that the particular bra isn't the right shape of wire either (possibly too wide) so when you are trying the smaller size the wire is narrow so doesn't dig, but quadboob! When you go up a cup the wire widens, quad boob goes but it digs. So you may need something with narrower and slightly deeper cups. Maybe cleo?