When I had the chance to try out several pieces by Parfait, I knew that with a smallest band size of 30 and largest cup size of G, they wouldn't work so well on my 26HH body. I happen to have a good friend who wears a 28-30G, however, so I asked her if she wouldn't mind trying out the pieces. Here's what she had to say:

I tried the bra
in what is usually my bra size – a 30G. However, as you can see in
the photo, the cup is clearly too small. I tried resizing the straps,
everything you can do to loosen the fit of the cup, but still cut
across my breasts in a really unflattering manner. Some of this
might be due to the shape of my breasts, not just the size (I usually
avoid balconet bras, actually, due to the way they tend to fit). I
would suggest that if you are fuller breasted and like this bra (I
was really disappointed it didn’t fit, as I loved it!) you might
want to go up a cup size.
The second piece was a beautiful ivory chemise, also a 30G. It is a truly lovely piece, worthy of a bridal trousseau. Best of all, it fits like a dream. The cups on this item were full coverage, and the fit was right on target. The bodice flowed nicely, and I am not super thin, especially around the hips.
So, to summarize, this company makes absolutely stunningly beautiful lingerie. However, be aware that sizing of different cup styles can really make a tremendous difference in terms of fit. Based on my experience, if I was ordering something with a full coverage cup, I would stick with my standard sizing. On the other hand, if I was ordering something with a different cut – specifically a balconet style – I might go up a cup size."
-C.D. Smith
According to online reviews, Parfait by Affinitas pieces can work for some 28 band folks, if you're not a "small" 28. If you fit into their size range, I would definitely encourage you to give them a try. All of their pieces are gorgeous and very affordable. My only complaint is that they don't come in my size! I hope that someday, they are able to expand to include bands down to a 26 and cups up to a K or more! :-)