Marking threads for sewing: how to read and choose

Proper decoding of marking of threads for sewing directly affects the quality of the line and prevents breaks or looping on the inside of the product. If the coil has symbols 40/2 or LX 21It is not just a set of numbers, but precise specifications that determine whether the material will pass through the needle and how the seam will behave when wearing. Ignoring these parameters often leads to the fact that a thin needle tears a dense thread, and a thick one breaks the fibers of the tissue, leaving unaesthetic traces of punctures.

Understanding the designation system allows the master to instantly select fittings for a specific type of fabric, whether it is a weightless chiffon or rough denim. Modern manufacturers use several standards, and the confusion between the metric system and the Tex system can be worth the spoiled cut. In this material, we will analyze the basic codes found on the coils, and learn to accurately determine the purpose of the thread by its packaging.

The main numbering systems and their differences

The garment industry has historically developed different approaches to designating the thickness of the thread, which creates certain difficulties for beginners. The most common metric system, where the number indicates the length of the thread in one gram of weight. For example, a designation Nm 40 This means that one gram contains 40 meters of filament. The higher the number, the thinner the thread, which is an important rule to remember.

In parallel, there is a Tex system, which is based on the weight of 1000 meters of thread. Here the logic is reversed: the larger the number, the thicker the thread. If you see the markings Tex 40This means that 1000 meters of such a thread weighs 40 grams. Understanding this difference is critical when ordering materials from different suppliers or when working with imported equipment, where settings may require the input of the Tex value.

• 🧵 Metric system (Nm): The number shows a length of 1 gram (more number = thinner thread).
• ⚖️ System Tex (Tex): The number shows the weight of 1000 meters (more number = thicker thread).
• 🇺🇸 The American System (Cotton Count): It is often found on reels from the United States, denoting a length of 840 yards per 1 pound.

There is also a symbol, often found on household coils, where two numbers are indicated through a fraction, for example, 50/3. The first number here is the thickness of the elementary thread (twisting), and the second is the number of additions, that is, how many such threads are twisted together into one working thread. It's threadIt is the number of additions that affects its strength and volume.

Decoding of letter symbols on coils

In addition to the numbers, the label always has a letter code indicating the chemical composition of the fiber. This is no less important than thickness, as synthetics and natural fibers behave differently when heated by friction against a needle. For example, 100% Cotton It guarantees naturalness, but such a thread is less tensile than synthetics and can shrink after washing.

Symbols ll or LX They are a stainless stainless stainless stainless stainless stainless stainless stainless stain. However, it does not tolerate high temperatures of the iron and can melt if the ironing mode is incorrectly set. Combined threads, such as LHL (lausan cotton), try to combine the strength of synthetics and hygroscopic cotton, which makes them universal for sewing general-purpose clothing.

⚠️ Attention: Never use pure lausanne (LL) to sew pure cotton products if you plan to cook them later or wash them high-temperature. The synthetic thread will not sit down, and the cotton fabric will decrease in size, which will lead to tightening of the seam and the formation of “wrinkles” along the line.

Marked threads are used for special purposes Shh. (water-staple fiber) which dissolves completely in hot water. They are ideal for temporary sweeping of parts that cannot be neatly chipped with pins, or for fixing the snags on the front side of the product. After sewing, it is enough to rinse the product, and the thread will disappear without a trace.

Table of correspondence of thread and needle thickness

The correct selection of the needle to the thickness of the thread is the key to the absence of passes stitches and breaks. If the needle's eye is too narrow, the thread will rub against its edge, heat up and tear. If too wide, the loop does not form correctly and the lower invader will not be able to pick it up. Below is a table that helps you navigate the ratio of parameters.

Tissue type/Prescribing	Metric number (Nm)	Needle number (Europe)	Example of marking
Chiffon, organza, bathista.	75 - 90	60 - 70	80/2, 90/2
Blouse fabrics, silk.	60 - 70	70 - 80	65/2, 75/2
Dress fabrics, costumes	40 - 50	90 - 100	40/2, 50/2
Jeans, coat fabrics	30 - 40	110 - 120	35/3, 40/3
Shoes, leather goods	10 - 20	130 - 140	20/3, 18/6

When working with knitwear, it is important to pay attention not only to the number, but also to the elasticity of the thread. Ordinary sewing threads can burst when the canvas is stretched. There are special markings for knitwear, for example, Stretch or using textured threads that feel fluffy and soft. Such threads are often used in overlocks and sewing machines.

Strings for household sewing machine and overlock

Domestic sewing machines most often require threads on standard-sized coils with numbers from 40 to 60. The use of too thick threads (below 30 numbers) can lead to malfunctions in the shuttle assembly, since the thread will not have time to pass through the tension disks. For top threading, standard coils are usually used, and for the bottom (in a spool), the same threads or special reels of larger volume can be used.

Overlocks are more demanding on the quality of the winding and smoothness of the thread. Here, cone reels are often used to make the thread run off without jerking. Marking 50/3 or 60/3 It is the standard for a 4-strand overlock. If you take a thread with fewer additions (for example, 2 instead of 3), the seam can be flat and inelastic, which is critical for processing the edge of the knitwear.

For flatlock machines, threads with a special twist structure are often required so that the top stitch lies flat and does not wind. Sometimes the filling uses threads of different numbers: a thinner thread is put in the needles (for example, 75-80 number), and in the lower loops - a more voluminous and soft (50-60 number) to create a decorative flat seam.

Special and decorative threads

In the arsenal of the master should be not only standard reels, but also specialized types of threads for specific tasks. Mononize (silk) is used for secretly filling the bottom of products, when it is necessary that the seam is completely invisible. It is soft (for delicate fabrics) and hard (for dense materials and curtains). You need to work with it carefully, as it can melt from a hot needle.

For decorative lines and embroidery threads with marking are used Decor or Embroidery. They have a special glossy coating and often a smaller twist to cover the fabric with a dense carpet. Use them for grinding parts can not be - they do not have the necessary tearing load and quickly wear out in the seam. Their fate is the upper decorative line or embroidery.

⚠️ Attention: When using metallized threads, be sure to reduce the sewing speed and use silicone grease for threads or special needles with a large ear. The metallized coating quickly wears off against the needle, causing breaks and contamination of the machine mechanism with metal dust.

Another important type is the quilting thread. They usually have labels. Quilting and number 40 or 50. Their feature is a wax coating or special treatment, which prevents the formation of down and pile when zip-proofing a multi-layered “sandwich”. This allows the needle to easily pass through all layers without leaving a villi behind.

How to store threads so that they do not lose properties?

The threads should be stored in closed containers or boxes, away from direct sunlight. Ultraviolet destroys the structure of polymers, making the thread brittle. It is also important to avoid high humidity, which can lead to the formation of mold on natural threads (cotton, silk) and corrosion of metal elements in the composition of some decorative threads.

Frequent mistakes in choosing threads

One of the most common mistakes is using old stocks of threads that have been lying on the shelf for decades. The thread has its shelf life: synthetic becomes brittle (breakable), and natural can simply rot or be covered with mold from the inside of the coil. Before using an old reel, be sure to take a test for breaking your hands - if the thread breaks without effort, throw it away without pity.

Another mistake is to ignore the color of the bottom layer. When sewing transparent or translucent fabrics (chiffon, organza, thin knitwear), the color of the thread in the spools should perfectly coincide with the color of the upper thread and fabric. Otherwise, due to the features of the weave, the lower thread can "look out" on the front side, spoiling the appearance of the product. In such cases, it is recommended to use threads in the color of the main tissue or special transparent threads.

Also, masters often neglect the quality of threads, buying the cheapest options for weight. Such threads often have an uneven thickness along the entire length, which leads to constant failures in the machine: it loops, then pulls, then breaks. Saving on threads when sewing expensive fabric is a false savings that can lead to spoilage of the entire product.

FAQ: Frequently Asked Questions

Can I use different manufacturers in one joint?

Technically possible, if the number (thickness) and the composition of the thread match. However, manufacturers use different dyes and lubricants. When washing or ironing threads can behave differently (different shrinkage), which will lead to deformation of the seam. For responsible products, it is better to use threads from one batch and from one manufacturer.

What does the "L" or "LL" marking on the coil mean?

The letter "L" means lausan (polyester fiber). LL is a 100% lausan thread. It is a strong synthetic thread that is resistant to rot and abrasion, but it is afraid of the high temperatures of the iron and can slide in some tissues. Suitable for sewing outer clothing, bags, products that do not require frequent ironing.

Which threads are better for sewing jeans?

For grinding denim fabric (lads, side seams) are used threads of increased strength, usually marked as Jeans or have the number 30-40 (3-4 additions). For decorating (decorative stitching) take thicker threads (No. 20 or No. 30) of golden or contrasting color, often marked with a marking. Top Stitch.

Why does the thread always break when sewing?

There may be several reasons: the thread does not correspond to the number of the needle (too thick for a narrow ear), the needle has blunted and damages the fibers, the tension of the thread is incorrectly tuned, or the thread itself has dried up and become brittle. Also check if there are no burrs on the path of the thread (in the needle holder, on the shuttle).