Essential guide to sewing machine threads
Which is the best thread to use with your sewing machine? Our guide to sewing threads will help you pick the best type for your project so you can get the best results from your stash!
So, you’ve chosen your fabric and are ready to start stitching – but have you got the right thread? Choosing the right sewing thread can make a big difference to your results. Our sewing machine skills for beginners series continues with a focus on sewing threads and how to pick the right one for your latest project.
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There are so many different varieties of sewing machine thread available that it can be tricky to choose the right one to use. It’s not just about finding a colour to match your fabric – you’ll need to consider other things, too, like the fabric’s thickness or stretch. It’s worth taking the time to pick out the right thread, because it’ll really make a difference to the stitching experience and your finished project.
Choosing your thread
Although an all-purpose polyester thread will work well on most material, if you’re working with a slightly different fabric, such as stretch or heavyweight, then the general rule is to use the same type of thread as the fabric. So, for example, if you’re sewing with 100% cotton material, use 100% cotton thread and match the thread weight to your fabric. Sometimes your sewing pattern or instructions will give you advice on which type of thread you should use. If you can’t find an exact colour match, choose a thread one to two shades darker than the fabric, as light thread will stand out more – unless you want to make a feature of it, of course! And, most importantly, ensure you buy good-quality thread. Send an email to email@example.com to find your nearest thread stockist.
Reading a spool
The end of the thread spool lists the fibre content, the manufacturer and colour number (invaluable if you need to buy more thread later), and often its weight and the number of plies (strands) that are twisted together. This is usually listed with two numbers – the higher the first number, the finer the thread.
Types of sewing thread
There are several types of thread, which can be spilt into categories depending on what they’re made from. Within these there are different strengths (number of plies) and thicknesses (weights).
Cotton thread has very little stretch and is great for delicate projects, particularly for cotton fabrics or sheers, but not for stretchy fabrics. Most cotton thread is mercerised, which means it has gone through a series of chemical processes that increase the lustre of the thread and make it more water and dye-absorbent. This means it’s less likely to run.
These are strong and have some stretch. They often have a wax or silicone finish that allows the thread to slip through the fabric with little friction. This thread is also suitable for stretch fabrics such as synthetics and knits. Cotton-wrapped polyester thread can be used with most fabrics, too.
Threads made from a variety of materials, such as silk, again should be matched to the thread content of your fabric.
Find a thread! Pick the right one for your project
Here's a guide to our favourites...
Polyester sew-all thread
Above left: This 100% polyester thread is an all-purpose thread, comes in a vast choice of colours and is widely available. You can use it for machine sewing as well as hand stitching, and it will work with most fabrics. It’s strong, yet it has stretch, making it ideal for knit fabrics. Needle size: 70-90.
Above centre: This environmentally sound thread is made from 100% recycled polyester. It’s as strong as polyester thread with the same stretch, so can be used for the same types of projects. Recycled PET bottles are used to make it; one bottle makes around 1000 metres. Needle size: 70-90.
Above right: This 100% polyester thread is perfect for working topstitching as it’s really strong and can be used for a decorative finish. It has a silk-like gloss and a good stretch. Use a bigger needle for this thread, as it is thicker than ordinary polyester thread. Needle size: 100-120.
Above left: This heavy-duty polyester thread is ideal for sewing upholstery and soft furnishings. It’s also perfect for seams that will be under strain a lot, such as on work trousers or jeans. It can be used for heavy woven fabrics and leather, and is tear- and abrasion-resistant. Needle size: 70-100.
Above centre: Cotton thread comes in a few different thicknesses. Cotton 30 is slightly thicker than usual, so is ideal for machine quilting. It’s often used in machine embroidery, as it gives a bold stitching line. It’s available in solid as well as variegated colours for decorative effects. Needle size: 80-90.
Above right: Size 50 is one of the most common cotton threads. It’s a medium-thickness cotton so is suitable for a range of fabrics, from lightweight and medium cotton to heavier linens. It’s a soft and supple thread but has little give, so isn’t suitable for stretch or knit fabrics. Needle size: 60-80.
Above left: Silk is a fine yet strong thread ideal for sewing on silk and wool. Silk threads are smooth and fine so won’t leave holes in your fabric, and are perfect for tailoring, especially for working seams. Its lustre makes it ideal for decorative topstitching as well. Needle size: 80.
Above centre: This is a heavier-weight thread for stitching denim and making or mending jeans by hand or machine. You can use it to overlock seams, work straight seams or topstitch. It comes in jean colours as well as this bi-colour thread, which blends in with the denim. Needle size: 80-100.
Above right: Metallic threads can be used for machine embroidery and are mainly decorative. They are usually made from a mixture of polyester and other artificial fibres such as polyamide. They’re ideal for ornamental stitching and come in many colours and finishes. Needle size: 100-110.
Above left: Elastic thread is also known as shirring thread, as it is used for gathering or ‘shirring’ fabric. The thread comes in many colours but is only used in the bobbin. It has to be wound by hand to get the right tension. Match the elastic thread to your fabric, as it will be visible on the underside.
Above centre: This is a fine, flexible thread that is soft, strong and smooth and won’t melt when ironed. It’s ideal for projects where the stitching needs to be strong but hidden, and is available in dark or light to match your fabric. It can be used as a top thread, in the bobbin, or both. Needle size: 60.
Above right: These are wound on large cones, as overlocking uses more thread than stitching a seam on a standard sewing machine. Translucent thread, a thinner semi-transparent coloured thread that is often used for blind hemming, is also available. Needle size: 60-80.
Simply Sewing magazine’s Technical Editor Roisin loves every part of the dressmaking process, from sketching to sewing the final design, and enjoys working with luxury fabrics such as silk and chiffon. She’s a sewing pattern pro with a skill for adjusting and hacking patterns to fit and for editing dressmaking instructions to make them accessible to sewists of all abilities. Before she came to Simply Sewing, the tea-drinking fabric-lover ran her own handmade Lingerie Etsy shop. She drinks a lot of tea and shares a mix of dressmaking projects and fashion history on her Instagram @roisin_handmade.