A seam that comes apart after being sat on a few times is rarely the result of the fabric alone. Often the sewing thread is too thin, not strong enough or simply unsuitable for the way the furniture is used. If you are asking yourself how to choose sewing thread for a chair, cushion, sofa or camper interior, don't start with the colour, but with the material, the load and the machine.
In upholstery, thread has to endure much more than in a blouse or curtain. Seams are stretched, subjected to friction, and on heavily used furniture the thread must keep its shape and strength for years. The right choice gives a neat stitch and a finish you can rely on.
How do I choose sewing thread for my project?
First look at exactly what you are going to sew. A scatter cushion in light upholstery fabric needs something different from a dining chair in faux leather or a sofa that is used every day. The position of the seam also plays a part. A visible topstitched seam must look crisp, while a seam on the underside above all needs to be strong.
Then decide whether you will sew by hand or with a sewing machine. For upholstery fabrics and faux leather, a sturdy machine with a suitable needle is usually the best choice. The thread must run smoothly through the needle, tension discs and hook. An extra thick thread can look great, but causes problems if the needle is too small or the machine is not set up for it.
When choosing, always consider these three questions: what material am I sewing, how much pulling force will the seam take, and should the thread stand out or blend in? With that as a basis, you avoid most disappointments.
First choose the right thread material
The material of the sewing thread determines how strong, hard-wearing and suitable it is for your application. For upholstery work, synthetic threads are generally the most practical choice.
Polyester: the reliable all-rounder
Polyester sewing thread is an excellent basis for many upholstery projects. It is strong, hard-wearing and has a slight stretch. That small elasticity is useful with fabrics that move or are under tension, such as a seat, back cushion or loose cover. Polyester also resists moisture well and fades less quickly than many natural threads.
For the DIYer who is reupholstering a chair or making cushions, good-quality polyester thread is usually the safest choice. It is also widely usable for professional applications, provided the thickness suits the fabric and the load.
Extra-strong polyester for seams under load
With thick upholstery fabrics, faux leather, Skai, vinyl and leather-look materials, a standard all-purpose sewing thread often has too little body. In that case, choose extra-strong polyester thread. This thread is made for seams that have to absorb more force, for example on seats, armrests, piping and edges of cushions.
Extra-strong does not automatically mean it is the best solution for every seam. On a fine velour, a very thick thread can pucker the fabric or produce too coarse a stitch. The thread must be in proportion to the material. A sturdy, full-bodied upholstery fabric can take a thicker thread well. For a fine fabric, it is better to choose a more subtle thread of sufficient quality.
Nylon and other specialist threads
Nylon thread is very strong and hard-wearing, but is mainly used when high tensile strength or specific technical properties are required. Think of certain applications in automotive, bags or heavy decorative work. For regular furniture upholstery, polyester is often more practical, partly because it resists light and long-term use well.
Cotton sewing thread goes nicely with natural materials and traditional sewing, but is less logical for heavily loaded furniture seams. It has less stretch, can wear more quickly and is more sensitive to moisture. Use it mainly when appearance or historical accuracy is more important than maximum durability.
Pay attention to thickness, strength and stitch appearance
The thickness of sewing thread is not always indicated in the same way. You will see, for example, numbers, tex values or terms such as all-purpose, strong and extra strong. More important than a single figure is the result: the thread must be strong enough without overloading the fabric, needle or machine.
A thinner thread gives a refined stitch and works well on light or densely woven fabrics. A thicker thread fills the seam more and is more visible. That is ideal for decorative topstitching on faux leather, corduroy or coarser woven upholstery fabrics, but less suitable when you want an almost invisible seam.
Always test on an offcut of the same fabric. Sew a short seam, carefully pull the fabric open and look at the stitch on both sides. Does the top thread pull the bobbin thread up, or do you see loops on the underside? Then the thread tension is usually wrong. Does the fabric pucker? Then the thread, needle or tension may not be well matched.
Match thread, needle and sewing machine
Good sewing thread only performs well if the rest of your equipment is right. With thicker thread, use a needle with a sufficiently large eye. Otherwise the thread rubs too much, breaks more easily or runs stiffly through the machine. For upholstery fabrics, universal needles are often suitable, while faux leather and Skai benefit from a leather or Microtex needle, depending on the material.
Also pay attention to the needle size. A needle that is too thin can bend or break with heavy fabrics. A needle that is too thick makes large holes that remain visible, especially in faux leather. With faux leather this is extra important: wrongly placed needle holes do not close up by themselves. Test stitching is not an unnecessary step here, but smart preparation.
Preferably use the same type of thread for the top and bobbin threads. Combining a thin bobbin thread with a very thick top thread can sometimes work technically, but requires experience and precise adjustment. For a strong, balanced seam, the same quality top and bottom is the most reliable choice.
Choosing a colour: invisible or decorative
The simplest rule is to choose a thread as close as possible to the main colour of the fabric. With a melange, woven or bouclé upholstery fabric, you usually choose the colour that is most dominant from a distance. A slightly darker thread is often less noticeable than a lighter shade, because dark stitches seem to sink into the seam more.
With faux leather, Skai and leather-look materials, on the other hand, the thread can be part of the design. Contrasting thread emphasises lines and gives a crafted or rugged look. Think of light stitching on dark cognac faux leather, or black thread on a light covering. Bear in mind that every small deviation will then be visible. A contrasting topstitched seam therefore requires a consistent stitch length and straight guidance.
If in doubt, a colour test is wise. Lay a few threads on the fabric and look at them not only indoors but also in daylight. Warm beige, grey and green shades in particular can look unexpectedly different under different light.
Take use and environment into account
A decorative pouffe in a quiet living room has different requirements from a bar stool, restaurant chair or camper cushion. With intensive use, abrasion resistance and seam strength are decisive. In that case, choose strong polyester and work with sufficient seam allowance. Even the best thread cannot save a seam if there is too little fabric next to the stitching.
For outdoor use or furniture in a conservatory, UV resistance is extra relevant. Not every thread is made for prolonged exposure to sunlight. For a project that gets a lot of sun, a thread specifically suited to this is a wiser investment than a standard reel.
Cleaning also counts. Fabrics and faux leather that are wiped regularly or cleaned intensively need colourfast, hard-wearing thread. A seam that starts out strong but becomes faded or fluffy over time detracts from the end result.
Common mistakes when choosing sewing thread
A common mistake is using ordinary household thread because it is already in the sewing box. For a small repair that may be enough, but for a sofa cushion or seat the risk of wear is high. Another mistake is choosing thread that is too thick on the assumption that thicker is always stronger. If the machine, needle and fabric don't cooperate, you get irregular stitches and unnecessary damage.
Colour is also sometimes underestimated. A thread that looks perfect on the reel can be surprisingly prominent in a long seam. Especially with faux leather and plain velvet, it pays to sew a test seam first. At the same time, check that the stitch length is right. For furniture work, a slightly longer stitch often gives a calmer and stronger look than very short stitches that can perforate the fabric.
At BLADI upholstery fabrics you will find threads and upholstery supplies for a quick repair as well as professional upholstery work. If you are torn between two thicknesses or colours, always start from your fabric and application. That leads to a better choice than just looking at what is printed on the reel.
A well-chosen sewing thread usually goes unnoticed – exactly as it should. But in the strength of a seat, the crisp line of a piping and the comfort of a carefully reupholstered piece of furniture, it makes the difference every day.
