The 32J bra has a bigger band than the 30J bra. The 32J bra has wider cups but they are both about the same depth.
30GG - Cleo » Kali Balconnet Bra (7561)
Comparing a 32J Panache Jasmine Balconnet Bra (6951) with a 30J Cleo George (5131)
30F - Cleo » Mimi Padded Balconnet Bra (8091)
32GG - Cleo » Marcie Balconnet Bra (6831)
30FF - Fantasie » Smoothing Moulded T-shirt Bra (4510)
lemma/lib/en/nouns.ex at master · xiamx/lemma · GitHub
30G - Panache » Envy Balconnet Bra (7285)
30E - Curvy Kate » Ellace Balcony Bra (CK4401)
32G - Gossard » Glossies Moulded Bra (6271)
30J - Cleo » Meg Balconnet (6751)
32E - Panache » Andorra Full Cup Bra (5675)
34F - Panache » Jasmine Balconnet Bra (6951)
30F - Panache » Envy Balconnet Bra (7285)