I go without at home or if I'm wearing a fairly skin-tight cami underlayer. Otherwise I wear a simple stretchy cotton jersey bra, basically just to keep them from flopping about wildly. I have no idea what cup size I am, B maybe?

I've been following this discussion with great interest. I would second much of what Gigi wrote in her most recent post, from the idea of bra as accessory (I love that!) to the question of body-shaming. I should preface my remarks by adding that I in no way wish to question or to judge any individual woman's experience of her own body (or of her body in society, for that matter), nor what she chooses to do with it. That said, I think a critical cultural history of the t-shirt bra would make for fascinating reading. It is a phenomenon that has largely passed me by, probably for three reasons: my mother has always worn thin, lace bras and abhorred any sort of padding, I myself was so put off by this idea of padding when I was a teenager and young adult that I had few bras and often went without, and I moved to Europe in my mid-twenties. I think Angie remarked some time ago (although perhaps it was a commenter), that t-shirt bras seem to be an American preference, while European women are less concerned about the bra itself being visible beneath clothing, e.g.

I suspect that this idea of the t-shirt bra--which must have come about sometime in the 1990s?--was partly a technological innovation (molding rather than seaming), and one that almost certainly reduced production costs. The idea of the t-shirt bra, though, must largely be a product of marketing. I was surprised to hear about the experience of Astrid's sister, and (knowing next to nothing about the history of bosom-fettering in Germany), couldn't help but wonder to what it extent it is an end result of more globalized marketing. As for me, as I said, I moved to Europe, where I discovered bras that not only fit me, but that were beautiful creations. Despite the fact that, if pushed, I would probably have to agree with E on comfort, I haven't looked back.

Oh God, no, I am team wear a bra with padding actually. There is nothing worse than having a case of headlights in a business meeting.
As far as home, I try to wear a sports bra or half cami. I don't trust gravity.

I always thought a t-shirt bra was a bra made of t-shirt material. Which kinda sounds awesome. But it seems it's a bra meant to be invisible under a t-shirt?

I personally think wearing a textured lacy bra underneath some shirts gives an odd crunchy appearance to the bosom which is not all appealing. It just looks unnatural. I tried a gorgeous La Perla bra set for a while but it looked so bad when clothed I ultimately decided that it wasn't workable.

I have seen a few heavier, very very well-endowed women with no bra and breast that clearly hit their waist. Is it just too hard to find a bra in those sizes? Or is it uncomfortable to bear the weight where a bra redistributes it? Honestly, I am curious, because it looks really uncomfortable.

A correctly fitted bra should not redistribute the weight uncomfortably. Most of the weight should be held by the band around the ribcage. There should not be pulling on the shoulders. However, there was some study that said 80% of women wear the wrong size bra.

I've had no luck with lacy bras actually worn under something - as opposed to on their own. They itch and they show through. Non padded bras for me basically are equivalent to going without in terms of nipple show through. So t-shirt bras - comfortable, soft, gently padded, no extraneous doodads, are my friends.

I wore padded bras in my early 20's also because I wanted to create a bit of hourglass - I had hips but not the equivalent up top. Under tank tops with cargo pants and tough boots it could be pretty hot when they fit right. (Starbuck is a style icon for me ).

I hear what is being said about the line between personal aesthetic preference/shame - I'd never want to censor the riot grrls or their feminist predecessors or women who just find it comfortable, and am cool with however one wants to resolve the body hair question. At times I've been totally fine with my own bra straps showing, or with a bra being visible under a black gauze shirt (kind of in a punk rock way). I think I've also once or twice worn only a bra before? There were these college raves, some people were just wearing body paint up top.... anyhow....

IK, I used to think that t-shirt bras were bras made out of t-shirt material too! But they're not. They're bras with thick molded cups, and like you say, the point is to have them be invisible under a t-shirt. I didn't realize they were mostly an American thing, as Faith says. I don't like them at all, as they feel like armor to me. :^) I do have a bra with molded cups from VS, and I will wear that when I need to be completely "seamless," as it were, but it's still not anywhere as thick as a t-shirt bra.

I've had problems too with some lace bras giving texture underneath shirts. Some are OK, though. I would try some different ones if you're still interested in the idea. I think that if they are really well fitted, they might not show so much, since they'll be like a second skin. My VS bralettes are lace, and they don't show.

I have to wonder about Austin, IK, that you see so many well-endowed ladies without a bra! I never see one up here in Minnesota. But then again, it's winter for six months out of the year, so I wouldn't notice since everything's covered up. :^)

I've seen them many places, G, from California to Portland to Austin. Gigantic bosoms with no support.

Jumping into the conversation here!

Personally, I only wear a bra whenever I go outside, do sports, or have guests at home. My bust isn't all that big, but it is large enough that I can feel "them" jiggling whenever I go without a bra. Common sense dictates that, in my situation, I should be wearing a bra even at home - however, I grew up not wearing a bra at home, so I'm used to a certain amount of bouncing and will happily go without a bra until one of the three situations above comes up. The fact that I always have to wear a slightly too tight bra so that the band doesn't ride up because of my back fat gives me even more reason to go without at home.

That being said, I do believe that all women, regardless of bust size, should try to wear a bra whenever they go outside. Ignoring the size of your bust, I say wear a bra so that your nip-nips don't shine through! Unless you're wearing something that's made out of really thick material (e.g. down jackets), from personal experience, your nip-nips will most definitely be visible!

Which brings me to another topic - bras with padding. My nip-nips protrude quite a bit, so all my bras are padded. I hate lots of padding though, so they are only very lightly lined. The only bra that I own that's quite heavily padded is Maison Close's Villa Satine bra. (If you're looking for a slightly lacy bra that'll look pretty decent under your clothes, I find that this bra isn't too bad. Only one seam shows through. None of the lace does!)

...I guess that's enough on bras for now. Haha, is my interest in this topic shining through?

Edit: Included some photos of me wearing the Maison Close bra with a really thin and light undershirt from Uniqlo. Lace is invisible and seam is almost invisible. I'm pretty sure that a thicker top should disguise the seam pretty well! Also, in general, I find that cowl neck t-shirts do a fabulous job with disguising seams and laces. And if you don't mind going for less lace, there are many bras out there that should blend in with other tops quite well! Just be wary of the seams - but don't be afraid to try them out! Seams work wonders.

I bought some of these a few months ago and they work better than expected. For the first time in ages I don't have to go super padded if I don't want to.
http://www.dimrs.com/

That being said, I'm a Le Mystere tee shirt bra kind of girl. That thing is amazing!! I've always been team no padding, but this doesn't add, and actually makes me look smaller (dunno how that works). I think it has to do with the shape of the bra + the amount of molding underneath the cups that just make you look slimmer.