"Camicia" is a shirt. "Maglietta" is a t-shirt. "Maglione" is a sweater. "Maglia pesante" is a heavy sweater. Here's a link to a discussion on the difference between "maglia" and "maglione": http://forum.wordreference.com/showthread.php?t=992767
Except when it's not. Here's a page from Zara and you'll see a lot of things that aren't Teeshirts are called maglie. http://www.zara.com/it/it/donna/maglie-c358007.html
yes, so they were picky about it being a pink jersey (not a pink blouse), but it cannot be a thin jersey, it must be a thin shirt. I know it is too much to ask, but when giving corrections it would be really nice if there was an explanation from DL as to the difference. I find myself coming here to the comments and not always getting an explanation of the distinctions. So, I'm gathering a maglia is a knit shirt (e.g. like a polo). A camiche must be a cloth shirt??? I already knew a maglione was a sweater. And I learned a new word today maglietta, which is a t-shirt.
I'm keeping a running dictionary of all the words in the DL dictionary, and from a much earlier lesson, maglia was translated as being a "sports shirt". So there is some leeway here. In the context of English football (soccer) for example, you can say "he wore the shirt with pride", meaning the t-shirt/jersey that you wear while playing for your team.
Sottile is more for inanimate objects, magro for animals and people. For example: "Un foglio sottile" (A thin sheet) but "Un cane magro" (A thin/skinny dog). However you could also see sottile as an adjective for a person, but with a different meaning! In fact if i say "Lui è un uomo sottile" I'm saying "He is a subtle man".
You are absolutely right. Maglia strictly speaking means knit or knitting from which you get:
Maglia: a sports shirt or jersey (as in Maglia Azzurra worn by the Italian's National Football Team); Maglione: Sweater, Pullover Jumper Cardigan; Maglietta: Tee shirt or Undershirt.