Have you ever wondered what all of those numbers on the end of your Aurifil thread mean. Here is a wonderful graphic which gives you all the information you will ever need.
TIP: I am loving machine quilting with the 28wt hand quilting thread. It shows off your quilting very nicely, just remember you need to use a large eye needle to accommodate the thread. I typically use a 90/14 or a 100/16 size needle in my machine. You will need to experiment with your particular machine but it is worth giving it a try.