Invisible thread is one of those tricky sewing materials that can either make your project incredibly easy or an absolute nightmare. It’s ideal for hiding stitches, creating textures, and embellishment techniques like applique, but because it doesn’t behave like normal thread, some sewists find it tough to use. With a few tips and tricks though, you may discover it’s not nearly as challenging as you think. Check out these invisible thread basics!
What is it?
Invisible thread is a synthetic monofilament, meaning it’s made from just one strand of synthetic fibre. It’s available in both nylon (sometimes called polyamide) and polyester varieties. Each type has its own pros and cons. Polyester can handle high heat better, but nylon has a reputation for being softer and more invisible, though it may discolour slightly over time. In most cases, the right thread for the job depends on which you prefer personally. You may even find that the same type of fibre varies from brand to brand. For a breakdown of how different brands behave, check out this head to head comparison.
Why would I use it?
Monofilament thread is great for a whole range of projects, though it’s typically used where you want your stitches to be as unobtrusive as possible. Hence the name ‘invisible thread.’ It’s often used as the top thread in quilting, especially in multicoloured designs where a colourful thread would blend in against some fabrics and contrast with others. It can also be used to create textures in quilting without added colour, to attaches appliques, finish bindings, and more. It’s fine to use with both knit and woven materials, and though it’s lightweight enough for delicate fabrics, it’s also sturdy enough for heavier material, though it shouldn’t be considered a utility thread or for ‘heavy duty’ projects. It’s used less frequently in hand sewing, but can be great for adding beading or other embellishments to sheer fabrics, like those commonly found in bridal wear and accessories.
Tips & Techniques
- Use a smaller needle Monofilament tends to be considerably smaller than normal thread, and should be used with a smaller needle. In fact, the smallest needle you can find will probably work perfectly—just be sure not to use it with your everyday thread, as the smaller eye will cause regular threads to shred and fray. If your machine doesn’t have an automated needle threader, use a dark coloured permanent marker to colour the tip of your thread so you can see it while threading the needle. This will be cut off and discarded after starting your seam.
- Practise on scrap fabric! You will need to adjust your sewing machine’s settings to work properly with monofilament. Start with your top thread tension as low as it will go, then slowly increase it until you see correctly formed stitches.
- Take special care with bobbins Monofilament is typically only used in the top thread of your sewing machine. Since it’s stretchy, it takes extra adjustment to use it in the bobbin as well. If you do need to use it in your bobbin, wind it very slowly and only about half full. The heat from winding too quickly causes the thread to stretch, making it easy to overfill the bobbin. You’ll also need to adjust your bobbin tension, which, depending on your machine, may mean adjusting the bobbin case as well as machine settings.
- Lock your stitches With monofilament, you want to be sure to backstitch at the beginning and end of every seam. Because it tends to stretch, you may find that your stitches pull free as you sew unless they’re firmly locked in place.
- Use ‘smoke’ coloured thread with dark fabric Perfectly clear monofilament tends to have a bit too much shine to hide against dark fabric, so if you’re using deep colours in your project, try a ‘smoke’ coloured monofilament instead. These tend to be slightly greenish or greyish in colour. You may need to test a few to find what works best for your project.
- Don’t listen to the urban legends Monofilament thread was originally used in upholstery, so when it first became available for home sewists, it hadn’t changed from the heavy, industrial material used in commercial sewing machines. It was tough, inflexible, and hard on machinery and fabrics alike, often cutting into soft fibres and causing breakages and tears. Today’s invisible threads have come a long way. They’re not going to cut your cotton fibres or damage your sewing machine—at least, as long as you’re using it correctly.
- Double check your thread path If you find your monofilament thread isn’t working well despite adjusting the tension, try re-threading your machine. It’s so tough to see that you may accidentally miss some of the loops and guides in your thread path without realizing it, causing tangles and tension issues. If your thread is too fine to stay in place well, try adding extra guides by taping a safety pin or two to your sewing machine along the thread path, away from any moving parts. The spring end of a safety pin, where the wire forms a solid loop, makes an excellent thread guide.
- Try it for beading If you’re stitching beads to your project as embellishment—especially small and delicate beads—monofilament is a good option for attaching them. It’s stronger and thinner than other threads, which makes it easy to get through even tiny beads. Keep in mind, though, that monofilament can be tricky to knot by hand. Leave a longer tail than you usually would, and weave the end into your line of stitches instead of clipping it short. This can help keep your knot tight longer. Of course, hand-beaded fabrics should always be treated gently to avoid damaging either the fabric or the beads, so at least you won’t need to worry about rough handling!
While invisible thread does take some getting used to, it can be a real time saver in the sewing studio. Try it out on a small project, keeping these techniques in mind. The next time you’re looking to add subtle flair to a quilting project, or top-stitch across high-contrast prints without leaving a mark, you’ll be able to reach for your spool of invisible thread with confidence.