What is Stitch?
A series of repetitive stitches of one pattern is termed a stitch. A sewing stitch may be formed without any material, inside a material, through a material and on a material. BS 3870 (1991) categories the several types which are available into six stitch classes which cover the demands of joining fabrics together, neatening raw edges, or providing decoration. All types of stitches are formed by a needle penetrating into a fabric while transporting a sewing thread. It is essential to understand how the unique characteristics of every stitch type are dependent upon the mechanical actions of the sewing machine and fabric type, which determines the stitch properties.
The stitch could be formed in any of the three methods given below:
- Interlooping: It is created by passing the loop of one thread through the loop of another sewing thread. e.g. 401 double-lock chain stitch.
- Intralooping: It is created by passing the loop of one thread through the loop of the same thread. e.g. 101 single-thread chain stitch.
- Interlacing: One thread passes over another thread. e.g. 301 lockstitch.
The stitch properties are stitch size and stitch consistency. Stitch size includes stitch length (SPI – stitches per inch), stitch width (distance between the outermost lines of stitches) and depth (distance between the upper and lower parts of the surface stitch). Stitch consistency is the uniformity with which each stitch is formed in a row of stitches. There must be a compatibility of fabric, stitch and seam type, needle, thread and machine setting to achieve a good quality sewn product. Stitch lengths of about 2.5 mm are used for light- to medium-weight fabrics, 3 mm for medium- to heavy-weight fabrics and 3.5 – 4 mm for heavy and thick fabrics.
Types of Stitches in Garment Industry:
In the garment industry, various types of stitches are used to suit specific purposes, ensuring durability, functionality, and aesthetic appeal. Stitch classes are based on the type of loop formation by a sewing machine. Textile stitch types, classification and terminology are catalogued into six classes (as per BS3870/ASTM D-6193/ISO 4915:1991), which are identified by the first digit of the three digit numerals. Each class is further divided into several types which are identified by the second and the third digit. The British Standards Institution divides stitch types into six classifications, as listed below, and within each classification there are a number of variations known by a specific number.
- Class 100: Chain stitch
- Class 200: Hand stitch
- Class 300: Lock stitch
- Class 400: Multi-thread chain stitch
- Class 500: Over-edge chain stitch
- Class 600: Covering chain stitch
Specific stitch types are designated by the second and third digits of the number. For example, 301 is a single-needle lockstitch and is specifically identified by this number. Hundreds of different stitch types are used in the manufacture of textile products, but only the most commonly used will be discussed here.
1. Class 100: Chain Stitches
Class 100 chain stitches are formed by the intra-looping of a needle thread supply on or around the fabric. Single-thread chain stitch seams are often used for temporary applications due to their ease of removal. This is because each successive loop is dependent upon the previous loop for security, so once a loop is cut, the stitching can be easily unravelled and removed.
These kinds of stitches are formed from one or several needle threads, and are described by intralooping. One or several loops of needle thread are passed through the fabric and secured by intralooping with a subsequent loop after they are passed through the fabric (Figure 1). As each loop is reliant on the subsequent one, these kinds of stitches are very insecure and unravel very easily. The front and rear side of the class 100 stitches in the fabric is shown in Figure 2.
The stitch class 100 includes stitch types 101, 102, 103, 104, 105, 107 and 108. The class 101 stitch is the simplest one in this class produced from a single sewing thread. Since this stitch is insecure, it could be easily removed, and it is used for ‘basting’ operation in tailor-made garments. This kind of seam is normally not preferred for seaming operation as it is highly insecure but is widely used in multi-needle machines.
In the assembling of a garment it is vital to start and finish at a fabric edge, and that edge could be a small piece of temporary fabric secured to the garment edge by the stitches. After that, the fabric edges could be attached securely through the ends of the chain stitching to avoid the running back of stitches.
Class 100 chain stitches are used for:
- Basting – holding fabric pieces together temporarily before final stitching.
- Closing industrial sacking – holds the sack closed, but is easy to remove.
- Cornelli embellishment – up to 65 needles can be employed to produce decorative seams with the chain on the face fabric.
- Buttonholes and attaching buttons.
It is important that whenever 100 chain stitches are used, the end of the seam is secured to prevent the stitches from unravelling.
2. Class 200: Hand Stitches
The class 200 stitch types are categorized as hand stitches. These stitches are described by a single sewing thread and the stitch is held by a single line of thread passing through in and out of the fabric. Hand stitching is used at the high-priced garment production as the customer expects it at that price, and it may be the only way to a perfect finish.
The sewing machines have been developed to replicate hand stitching (stitch type 209) (Figure 3), which is used around the outer edges of tailored jackets. The machine is called a pick stitching machine. A double-pointed, centreeyed needle sews short lengths of thread in a simulation of hand-sewing.
The pick stitching machine could be set to sew a longer stitch on the top than at the bottom or vice versa.
Hand stitching is used at the expensive end of garment production. For example, these stitches are used in the lapel of jacket, coat, edge of the jackets, designed bed sheet, designed pillow cover and some luxurious items according to the consumer’s choice. Hand stitching is also used for tailoring and alterations, ensuring a perfect fit and clean finish.
3. Class 300: Lock Stitches
The class 300 lockstitch is often referred to as a double lockstitch. It is formed by interlacing a single needle thread supply with a bobbin thread supply from underneath, and has great strength and resilience if the correct types of thread, i.e. polyester/core spun, are used. Lockstitches are very secure, as a break in one stitch will not cause the seam to unravel, although it will compromise the overall seam performance.
The Class 300 stitches are formed using two or more sets of sewing threads, and are characterized by interlacing of the two or more threads. Loops formed by one group of threads are passed through the fabric and are held by the second group of thread. The top thread is called the needle thread and the bottom thread is known as the bobbin thread. The interlacing of thread in this class makes them secure and difficult to unravel. Straight lock stitch, 301 (Figure 4), with a single needle thread and a bobbin thread, is still the most common stitch used in the apparel industry.
Lock stitch has adequate strength for most purposes, provided appropriate sewing thread is used, with sufficient stretch, when it is correctly balanced. It has a similar appearance on both sides of the fabric. The front and rear side of the lock stitched fabric is shown in Figure 5.
The zigzag version of stitch (Class 304) (Figure 6) is generally utilized for joining trimmings like lace and elastic where a wider row of stitching is required. The main disadvantage of the lock stitch is that it uses a small bobbin comprising only a limited length to give the lower thread. Hence, it will exhaust quickly and changing of bobbins is time consuming in production.
Lockstitch is the most widely used stitch in low-volume production. Lockstitches are used for:
- Comfort/stretch garments, because the stitch can extend by up to 30%.
- Fabrics where it is important to have the same appearance on both sides.
- Top-stitching collars, cuffs, etc., because this is the only stitch that sews reliably around 90° when the fabric is pivoted at the needle point.
The two main disadvantages of lock stitch machines are:
- Multi-needle stitching with many closely spaced needles is not viable due to space required for the bobbin. So the maximum number of needles generally used on lock stitch machines is two.
- The limited stretch of lock stitch because of interlacing of threads which is unsuitable for edge neatening.
4. Class 400: Multi-Thread Chain Stitches
Multi-thread chain stitches are formed by inter-looping a needle thread with a separate looper thread on the underside of the fabric. This stitch is often referred to as a doublelocked stitch because each needle thread loop is interconnected with two loops of the same single under-thread. The stitch therefore looks like a 301 lockstitch on the surface but has a double chain underneath.
The class 400 stitches are created using two or more sets of sewing threads, and are characterized by interlooping of two sets of threads known as needle thread and looper thread. Loops formed in one set of sewing threads are passed through the fabric and are held by interlooping and interlacing with loops formed by another set of threads. The simplest version of this class of stitch, 401, is shown in Figure 8.
The chain stitch has the appearance of lock stitch in the front side of the fabric but has a double chain effect created by a looper thread in the backside of the fabric. A two thread chain stitch is stronger than a similar lock stitch and since no threads are interlocked with each other within the fabric, there is less probability to cause the type of seam pucker that occurs when tightly woven fabrics are distorted by the sewing thread.
The great advantage of this class of stitch is that both the needle and looper threads are run from large packages (cone) on top of the machine; therefore, there are no issues with running out of bobbins like with a lock stitch machine. It is often used on long seams in garments like trousers. The maximum sewing speed in lock stitch machine would be around 6,000 spm while in chain stitch machine 8,000 spm could be achieved.
Multi-thread chain stitches are used for:
- Joins where good strength and extension/recovery properties are needed, because this stitch has lower static thread tension and inter-looped threads.
- Joins where preventing pucker is important, because these stitches are less prone to pucker (again due to lower static thread tension and inter-looped threads on the underside).
- Long seams, because of continuous thread supplies.
5. Class 500: Over-Edge Chain Stitches
Overedge stitches are formed with at least one of the sewing threads passing around the fabric edge. There are many variations, and overedge stitching can use from one to four threads, of which only one is the needle thread. The needle thread provides the seam strength while the looper threads provide seam durability and extensibility. The looper threads are often chosen for softness and appearance.
These types of stitches are created using one or more sets of sewing threads, and have characteristic features that loops formed by at least one set of threads goes around the raw fabric edge. These stitches are generally called ‘overlocking stitches’. The most regularly used stitch types in this class has one or two needle threads and one or two looper threads and they form a narrow group of stitching line along the fabric edge with threads intersecting at the edge and preventing the fabric from fraying as shown in Figure 9.
All classes of stitches in this category have high elasticity, they do not unravel easily, and a trimming knife on the machine makes sure there are neat edges prior to sewing. Stitch class 503 is formed with one needle and one looper thread, and is less versatile, mainly used for edge neatening. Stitch class 504 is created from one needle thread and two looper threads and is utilized for edge neatening and, in the case of knitted fabrics, for joining seams. A combination of 401 and 503 stitch class is sewn simultaneously on one machine, where a joined and neatened seam is required that does not need to be pressed open and is generally called a safety stitch.
Overlock stitches are categorized by a number of ways and the most common way of classification is based on the number of sewing threads used in a stitch such as 1, 2, 3, 4 or 5 threads overlock stitches. Each of these stitch classes has a distinctive application and benefits as given below.
- 1-thread overlock stitches are used for ‘butt-seaming’.
- 2- and 3-thread overlock stitches known as ‘merrowing’ are utilized for seaming and edge neatening on woven and knitted garments.
- 4-thread formations known as ‘mock safety stitches’ provide extra strength while retaining flexibility.
- 5-thread formations, which employ two needle threads known as safety stitches, create stronger seams which are used for garment manufacturing.
Overedge stitches are used for neatening the cut edges of fabric plies (pieces).
6. Class 600: Covering Chain Stitches
The stitches in this class are made by utilizing three sets of sewing threads, namely, needle (A), looper (B) and spreader (C) thread as shown in Figure 10. The loops formed by the needle threads are passed through the loops of the spreader threads, which are already case on the fabric surface and then passed through the fabric where they are outer looped with loops formed by looper threads on the rear side of the fabric.
Stitches in this class are the most complicated of all types and could have up to a total of nine threads including four needle threads creating a broad, flat joining of elastic, braid of binding to the edges of garments like briefs with the possibility for a decorative top cover as well as the functional bottom cover over the raw edge of the garment fabric.
The complicated type of stitch in this class is known as a flat lock (606), which can be utilized to join fabrics that are butted together. Two trimming knives in the machine ensure that neat fabric edges butt together and four needles and nine threads provide a smooth join with good extensibility. It is commonly used on knitted underwear fabrics to provide a seam with low bulk that can be worn comfortably against the skin.
Class 600 stitch is widely used in garments requiring stretch, durability, and a smooth finish. They are ideal for activewear, underwear, knitwear, and swimwear, offering elasticity and resistance to frequent stretching and wear. These stitches are also used for decorative seams, ensuring a flat, aesthetically pleasing finish, and in technical applications like medical textiles. Their combination of strength, flexibility, and comfort makes them indispensable for stretchy and close-fitting garments.
Conclusion:
Different types of stitches in the garment industry ensures functionality, durability, and aesthetics. Each stitch type serves a specific purpose, enabling designers and manufacturers to create high-quality, visually appealing garments tailored to diverse needs and styles. These stitches are selected based on fabric type, garment purpose, and desired aesthetic.
References:
[1] Karthik, T., Ganesan, P., & Gopalakrishnan, D. (2016). Apparel Manufacturing Technology. In CRC Press eBooks. https://doi.org/10.1201/9781315367507
[2] Garment Manufacturing Technology. (2015). In Elsevier eBooks. https://doi.org/10.1016/c2013-0-16494-x
[3] Sinclair, R. (2015). Textiles and fashion : materials, design and technology. In Woodhead Publishing
[4] Textile and Clothing Design Technology. (2017). In CRC Press eBooks. https://doi.org/10.1201/9781315156163
