remember our sizing issue. well one of the factors playing into this is a thing called Bias.
let me try to explain is as best i can. you have a piece of material that is woven on a loom, and its woven in a back and forth motion. i'm choosing the simplest form here; so you essentially have a cross-hatch pattern.
now when sewing you want to find out which direction the threads run, this is called the grain direction. easiest way is to pull a thread on a raw edge from the bottom of your material and see which way it pulls off.
when lying out the paper patterns on the cloth for cutting you have to line the pieces up along the grain line. many pieces have marks and lines showing you which direction to lay it down. now on some of those pieces it shows you laying the piece diagonally along the grain direction. then on the pattern piece is usually a little chart that looks like the back of the envelope but it goes on about "the bias is 2.5 inches..."
turns out this is relatively important and i probably should have gotten more educated on bias before i started to sew. the reason some pieces are diagonal to the grain is because you want stretch. pull diagonally and there is some give/stretch on my material. you want to use this for certain pieces, the parts that go across breasts for example. what the little chart is trying to tell you is that if you are a size 14 according to the envelope you have to re-adjust using this little chart based on what they have figured out the bias/stretch will be. in my case because of bias my size 14 top is in reality a size 10-12 on the breast measurement; i'm supposed to make it smaller because its going to stretch because i'm pulling diagonally against the grain.
well thats part of my issue solved at least. thanks to my mom who walked me through this on the phone.