Well, i've been making this boob tubes to sell here in argentina...
They're made in a very stretchy black fabric, (i thing it's cotton + lycra, or sth like that) not very cheap.
Well, this's kind of a tutorial, so, i think i'll start explaining
(first tutorial, be patient xD)
The first thing you have to do is fold the fabric down to the middle and mark a rectangle. I've made one 60 cm x 35cm because it's a very stretchy fabric and i don't want it to fall (i'm 85 cm circumference in the chest so the shirt is going to be 70 cm, and it'll strach all the way to 85 cm)
It is long because i wan to fold 20 cm in so i have double fabric over my boobs and it's even stronger and if the fabric wasn't black it'd probably be a little see through so, as i don't want my underwear to be a public show, i'll make it like this
Here's a little sketch:
1. I've a 60 x 35 rectangle divided in three pieces. Sew the laterals up to the bottom mark (2). I've done it like this because my sewing machine hasn't got elastic sew, so i've got to leave a little cut to make it elastic when i finish the bottom.
3. Fold the upper 20 cm and sew the laterals again so it will stay in place.
Turn the thing inside out.
Now we've got a 40 cm length boob tube.
Make the endings, fold 1/2 cms from the bottom and 1/2 cms from the side cuts and sew.
Now it's black, plain and simple.
I've been thinking some stuff to put on them.
I've came out with this:
I added 2 D rings, one at the bottom and one on the top and got a piece of chain and added it (yeah, that's chain xD)
Fold a little rectangular piece of fabric in order to sew the D ring to the tshirt.
LOL i know this is kind of messy... Sorry for my bad english
I'll have pictures of them soon