This post is for any newbies out there who have heard or seen the title "Fat Quarter" and wondered what the heck it was, but felt too sheepish to ask.
(No worries - I was once one of you! And there are way more of us out there than want to admit it. So I'm here as your secret friend to get you in on the down low.)
Craft stores and quilt stores both carry pre-cut pieces of yardage called Fat Quarters. A Fat Quarter is a quarter of a yard of fabric, but it is cut in a different shape than a regular quarter yard of fabric. When cutting a quarter yard of fabric off the bolt, you are getting a piece 9" wide x the width of the fabric (around 42"-43".) Four of these cuts, create a yard.
A Fat Quarter is a piece of fabric cut 18" off the end of the bolt, and then cut in half on the fold. Four of these put together still make up 1 yard of fabric. Imagine a piece of paper cut into four equal horizontal strips compared to a piece cut once horizontally and once vertically to get four equal square-ish pieces.
One is not better than the other but one size might be more useful depending on the pieces needed for a particular pattern. For example, if you are using a pattern with strip piecing, or you want to cut a binding from that fabric, a regular quarter of a yard would be preferable because you would get longer strips and have less piecing to do. Also, say you want to cut a bunch of 4 1/2" squares. You will get 18 squares from a regular quarter of a yard, but you will only get 16 squares from a FQ. But a Fat Quarter shape comes in handy for other projects where you don't need the long skinny length, like a little Fat Quarter Bag, or something where you need a larger shape like the centers on this sunflower quilt.
So there you go. Now you can consume fabric with confidence.