I love to feel fabric. My mother used to take us along to the fabric store, and my brothers and I would look through the pattern books and run up and down the aisles, hands out and feeling the fabrics. When I pick a fabric, I pick first based on feel, second on color, and third on washing care. Of course, most times you do also have to pay attention to the fiber content and weave of the fabric, but you will find that even a 100% cotton fabric has varying feels and textures within that grouping.
For this project, if you are a brand new, novice sewer, please stick to a 100% cotton fabric with little to no stretch (pull both vertically and horizontally...every fabric has a little stretch diagonally). If you are more comfortable with different types of fabric, you can venture over to the cotton knits and jersey knits, maybe with a little spandex woven in. Because I am pregnant, and unable to predict just how large I will get, I have chosen a jersey knit with 10% spandex added.
When looking at colors and patterns, keep in mind that you will not be laying a pattern piece over your fabric. For newer sewers, you'll probably find it handy to choose something with a pattern that you can use as your cutting guide. Or, if you choose a solid color or difficult to follow pattern, you might use a cutting mat and rotary knife to help you cut a straight line.
So now you know what type of fabric you want. Let's look at dimensions and how much to purchase.
Fabric bolts have a sticker on their top telling you all about the fabric. It tells you fabric content (i.e. 100% cotton), how much total fabric is on the bolt (i.e. 8 yards), how to care for the fabric (i.e. machine wash warm, tumble dry low), and the fabric width (i.e 45 inches). When you pick a fabric to purchase, always take note of how to care for your fabric. Write it down or take a picture. You don't want to ruin a new project with the first wash!!
Let's go back to your dimensions. What is your Measurement C? This is how long you wanted your dress to be. If you want a 36" long dress, you certainly don't want to purchase a fabric that is only 28" wide. You would, at most, get a 27" long dress. So, now look for a fabric bolt that has at least 3" more in width than you want the length of your dress.
Now take your bust measurement (Measurement A) and multiply it by 2. This is how much fabric you will need to purchase from the bolt. For me, A x 2 = 56", or just over 1.5 yards, so I just asked the saleswoman to cut 2 yards. You also will need to realize that when the fabric is folded on the bolt, it very often isn't exactly equal. You may want to purchase at least 6" extra in order to square off your fabric. Otherwise you may find that at the top of the fabric, you have 60", while at the bottom you have 64" and you need 62".
For this project, I bought 2 yards of 60" wide jersey knit fabric. I want an ankle length dress. I also bought what was left of a patterned jersey knit bolt to make my scrawny, can-never-find-anything-appropriate-in-the-stores niece. That was about 1.38 yards of 42" wide fabric.
Also, purchase some elastic thread. Each of the spools shown contains 30 yards of elastic thread. I used up nearly a whole spool just in my practice, so I do recommend getting two right away. You'll also need thread in a color to match your fabric.
Bring your fabric home, and give it a good wash and dry. This will loosen the fibers and they will fall into their place. If you don't wash your fabric prior to cutting and sewing, cotton especially, your first wash will shrink your finished project and likely pull on the grain of the fabric, leaving you a mess that you'll probably never wear again! Then, iron your fabric according to the instructions on the bolt. If your fabric is wrinkly, your cuts won't be straight.
Next: Cutting the Fabric and Sewing the Dress!