Manufacturer · Fashion & Home Accessories
Cotton sewing thread is the choice when you sew cotton, linen, viscose or wool, when the item will be ironed at a high temperature or when the garment will be dyed after sewing. It is soft and matte, does not melt under the iron and takes up dye together with the fabric. It is not suitable for knitwear and heavily loaded seams, where polyester is the safer option.
What cotton sewing thread is
Cotton sewing thread is twisted from several strands of long-staple cotton. Most quality threads are mercerised – treated with alkali under tension to become smoother, stronger and slightly lustrous. The fibres are often also gassed (singed) to remove the fuzz on the surface. This way the thread runs evenly through the needle and does not leave lint in the machine.
The main characteristics that distinguish it from synthetic threads are:
- Heat resistance – cotton does not melt and withstands ironing at the iron’s highest setting.
- Low stretch – elongation at break is low, so the seam is stable but does not follow a stretch fabric.
- Natural look – a matte or slightly satin surface that blends with natural fabrics.
- Dyeing – the thread takes up the reactive and direct dyes used for cotton and linen.
Which fabrics cotton sewing thread suits
A good rule is for the thread to belong to the same fibre group as the fabric. Then both materials react the same way to washing, ironing and dyeing. Cotton thread is the natural choice for:
- shirts, dresses and skirts made from poplin, batiste, muslin and linen;
- baby clothes and nappies, where softness against the skin matters;
- bed linen, tablecloths, towels and other home textiles;
- wool fabrics and coats, for seams that are pressed intensively;
- quilted items, patchwork and handwork.
When you sew elastane, jersey, sportswear fabrics or lingerie, choose polyester or textured thread from the sewing threads range. There the seam has to stretch, and cotton will break at the first strong pull.
Thread thickness and needle
The thickness of sewing threads is marked with a ticket number – the higher the number, the finer the thread. An approximate guide for cotton thread looks like this:
| Ticket | Use | Needle (Nm) |
|---|---|---|
| 100–120 | batiste, poplin, light shirts and dresses | 70–80 |
| 80 | linen, velvet, medium-weight cotton fabrics | 80–90 |
| 50–60 | denim, canvas, home textiles | 90–100 |
| 30–40 | decorative and visible seams | 100–110 |
The thread should lie freely in the groove of the needle. If it is too thick for the needle, it rubs in the eye, frays and breaks. If it is too fine, the seam becomes loose, with skipped stitches.
How to sew with cotton thread without problems
- Use the same thread in the needle and the bobbin. Mixing cotton and polyester in one machine leads to different shrinkage and an uneven seam after washing.
- Reduce the upper tension slightly. Cotton is less elastic, and with tension that is too tight the fabric puckers.
- Stitch length 2.5–3 mm for most garments. A very short stitch on linen and cotton can “cut” the fabric along the seam.
- Clean the machine more often. Even gassed cotton leaves more lint than synthetic thread, especially at high speed.
- Store the thread away from sunlight and moisture. Old, dried-out cotton thread loses strength and starts to break.
When not to use cotton thread
Cotton is not universal. Avoid it for:
- knitwear and fabrics with elastane – the seam will not withstand stretching;
- outerwear, backpacks and bags under heavy load;
- outdoor products that are constantly exposed to sun and moisture – cotton weakens over time;
- synthetic fabrics that do not shrink – a cotton seam may pucker after washing.
In these cases the better option is polyester thread or a thread with a polyester core and cotton wrap, which combines the matte look with higher strength.
Colour and matching with accessories
If you cannot find an exact shade, choose a thread half a tone darker than the fabric – in the seam it looks lighter. On visible seams, a contrasting cotton thread underlines the natural character of the item and goes well with corozo buttons and cotton labels. The cotton threads range includes both natural and saturated colours.
Cotton thread in series production
In a garment factory the thread is chosen not for one garment but for a whole production run, so it is worth checking in advance. Sew a test sample with the same fabric, needle and machine speed, wash it according to the care label and iron it. Only then approve the thread for the run. This check shows in time whether the seam puckers, whether the colour bleeds and whether the thread withstands the speed of the industrial machine.
When ordering wholesale, specify:
- the type of cotton – mercerised or untreated;
- the thickness (ticket number) for each type of seam;
- the packaging – cones for industrial machines or smaller spools for ateliers;
- the colours, ideally with a fabric swatch;
- whether the item will be dyed or bleached after sewing.
This way the manufacturer can offer the right article the first time.
Cotton threads from Polkom
Polkom is a Bulgarian manufacturer of accessories for fashion, furniture, footwear and bags, with over 30 years of experience. We supply cotton and polyester threads together with buttons, zips and labels, so one order covers the whole garment. Send us the type of fabric, the thickness and the colours via the contact page – you will receive a quote and, if needed, a sample.
