|Different threads left to right: cheap, serger, hand quilting, upholstery, machine embroidery|
The photo above shows five different threads, all variations of white. Why on earth would a person have five different kinds of white thread? And what is a thread anyway?
Thread is typically spun of three (or more) different fibers, just like yarn. The fibers can be anything from cotton to something man made. The fibers used can be different weights to begin with, depending on what the manufacturer wants the outcome to be. Very fine fibers create a decorative thread, without a lot of ability to hold things together. Thicker fibers work harder. Think about the thread in a pair of jeans; it's much bigger than a thread in a blouse or shirt. So let's talk about the threads in the photo individually. All of the pictures below were cropped from the group picture above at the same size ratio.
|Super cheap thread|
This thread was purchased long ago, before I really knew (or cared) what I was doing. My guess is that I paid perhaps 50¢ for the entire spool of thread, and I got what I paid for. Notice the variation in the width and density of the thread, how fuzzy it is in places while not in others. Probably spun from pieces of fiber, this thread will have a tendency to break when put under stress. Sew a button on with this thread and you will likely be sewing that same button on again very soon. What do I use this thread for these day? Nothing at all, but I'm glad I still had it so that I could take a photo of it for this piece.
Serger thread is a fine thread which is sold on cones rather than spools. It is designed to be used in conjunction with two other threads (three total cones) primarily to preserve the edge of a piece of fabric. Alone, it's pretty fragile. You can actually see the twist in the thread toward the bottom of the photo. And note that it is a consistent width top to bottom. Serger thread isn't very strong as a single strand, since it's designed to be a part of a trio of threads. For light duty repairs, it works pretty well. Sewing that button on? Be sure to use a double strand of serger thread if you choose it.
|Hand Quilting Thread|
I use a lot of hand quilting thread, most of which is 100% cotton as well. Compare the density of the hand quilting thread to the serger thread above and you will immediately see how much denser this thread is. This is a very sturdy thread, designed to keep a quilt together through years of use and hundreds of laundry cycles. There's no loose fibers in it and it's incredibly tightly wound. It's a good button thread, too.
Like hand quilting thread, upholstery thread is very tightly wound with no loose fibers. It is a lot thicker than any of the other threads, as it is designed to hold upholstery fabrics together. These fabrics are much heavier (denser) than normal fabrics which is why it requires a heavier thread. If you want that button to never come off, upholstery thread will do the trick. But don't use this thread to hold a seam together in your favorite blouse; this thread is stronger than the fabric you're using it in, and may cause the fabric to fail.
|Machine embroidery thread|
Machine embroidery thread is a fine thread wound of polished fibers. Note how it appears to be three different colors in the photo. That is simply the different fibers reflecting the available light; the fibers are in fact all the same color. Machine embroidery thread isn't meant to do anything other than be decorative, as its name implies. If you use this thread for a structural purpose, you are wasting your time, as it will fail sooner or later (probably sooner).
So what thread do you need? Most people do very nicely with a single spool of white all-purpose thread. All purpose thread is just that - all purpose. Sew a seam together, sew on a button, repair a hem - whatever. All purpose thread will do the job.
The bottom line is, use a thread that's suited to the application so that it will last. If you're like me at all, having to do something a second time is just annoying!