Is there a rule of thumb about how much a dress can be taken in? I mentioned I'm going to look at a dress on Craigslist this weekend and it is a size 18 Maggie Sottero. It has an inner corset outside zipper. 18 is my street size so maybe it'll be too small for all I know. However the woman who is selling it sent me a picture and she is way larger than me and the dress looked a bit big on her even. So I was just inquiring if there is a rule that say "2 sizes is as much as you typically would want to bring in a gown" or something like that? If it matters it is a satin gown with ruching and buttons covering the zipper all the way down the back of the dress dress.