When you first start sewing, it can be confusing to choose which kind of thread to use, especially since they all look the same. You’ll be tempted to choose based on colour alone, however, using the right thread could make a world of difference on your next project (and will make sewing much easier!).
We’ve put together this basic thread guide to help you see the differences between types of thread and what they’re used for.
This is a very strong and durable thread with very little stretch or give. Because of this, it is best to stick with non-stretch light or medium weight cottons — using cotton thread with stretch fabrics may cause your stitches to break. 100% cotton thread is mercerized so that it has a nice lustre, absorbs dye and is smooth, which is helpful when quilting. It is also the most heat-resistant thread, so it can stand up to the hottest iron. This is the best thread to choose for quilting because it will last the longest and look nice.
Polyester thread is suitable for most fabrics, but especially knit and other stretchy fabrics because it has give. It is not as heat-resistant as cotton because it is synthetic. Most polyester threads have a wax or silicone coating to make it smoother. Button thread is thicker polyester thread used for decorative top-stitching and button holes.
All Purpose Thread
All purpose thread is typically polyester thread covered with cotton. This allows for a balance between the stretchiness of polyester, but some of the strength of cotton. This type of thread will work for most projects, and is probably your safest bet for machine sewing. This would be your best bet for applique because it will have some stretch, but will still have a nice lustre. When in doubt, use all purpose thread!
Nylon / Invisible Thread
In contrast to cotton and polyester threads that are made up of a few strands wound together, nylon thread is “monofilament,” made up of just one strand. It is good for synthetic fabrics, and is very flexible. Nylon threads are available in thicker weights for sewing heavy duty fabrics or upholstery. For upholstery, you can use nylon thread that is treated to resist mildew and rot. Like polyester thread, nylon thread is synthetic, so it can’t withstand high temperatures. Nylon thread is available in two shades, clear or smoke, to allow it to blend in to the project.
Embroidery thread is usually made of rayon or Egyptian cotton, so that it has a beautiful sheen. This thread is more decorative than functional — it is not very strong. Embroidery thread is available in every colour imaginable and can typically be found in skeins or on spools.
Silk thread is strong yet fine. Its elasticity and ability to be molded makes this thread good for sewing hems and tailoring. Because silk thread is so fine, it is great for basting and hems because it does not leave holes in your fabric.
Serger thread is typically cotton-coated polyester, but thinner than the all-purpose thread used in sewing machines or for hand sewing. This is because sergers go faster than sewing machines, so the thread will usually break rather than jamming up your serger. Even though one strand of serger thread is weaker than a strand of all-purpose thread, serging uses 3 – 5 strands at once, which adds a lot of strength. Serger thread is typically sold on large cones, and looks duller than other thread.
You can get elastic thread to elasticize areas of your project, or for decorative effects such as shirring. You can buy elastic thread in white, black and a few basic colours. It is usually used on the bobbin thread.