Silk is an expensive and multifunctional natural silk fiber made by silkworms, like the Bombyx mori breed, that go through the process of rearing. Rearing silkworms on mulberry leaves produce silk thread cocoons as they develop and these are harvested and processed into the highly valued silk fibers. Through the ages, silk has been highly valued for its truly luxurious soft and smooth touch, light weightiness, and silky feel, which made it a must-have for garments items, accessories, and home textiles, giving a sense of comfort and sophistication.

The value of silk is not only contained in its tactility but in other qualities such as natural luster, good drape, and temperature-regulating properties, thereby making its use widespread among many people. However, the environmental consequences of silk production are of concern because the growing of mulberry trees and energy-demanding processing have certain consequences. Sustainability is tackled by the use of organic silk farming and eco-friendly processing methods that generally have less impact on the environment. This is so because the future of the silk fabric involves other inventive options.

1. Mulberry Silk

Mulberry silk is the best and the most expensive kind of silk all of which are well-known for its exquisite quality and luxurious feel. It is obtained from the larvae of the silk-producing Bombyx mori silkworm, which consumes mostly mulberry leaves. The exclusive diet of Bombyx mori silkworm brings the silk in a position of superior quality, meanwhile, Mulberry silk deserves to be one of the finest and most expensive types in the industry.

Mulberry silk becomes unique for its smooth, silky, and lustrous texture. It comes with uniformity, durability, and natural gloss. The fibers are long, thin, and cylindrical so that the tight weave is achieved and the long life of the fabric is improved. The natural protein construction of Silk Mulberry is breathable, being cool to wear in different climates.

Mulberry silk normally is the most costly of all the silks in the market because of its excellent quality and very great production care. The labor-intensive process of farming silkworms, cocoons harvesting, and the resultant clean silk are the factors that explain the high cost.

A distinctive feature of Mulberry silk is that its quality is consistently high and there are no impurities or deficiencies in the fabric. Mulberry silk is famous for its being white or ivory which is the base every dye color comes in. Its variety of utilities grants Mulberry silk applicability in different sectors, from high-end clothes and lingerie to deluxe bedding and accessories.

Mulberry silk goes beyond softness, smoothness, and great luxury compared to other types of silk. The popularity of this silk mainly lies in its high quality, thus individuals with vast knowledge about silk textile materials prefer it. Mulberry silk stands for the ideal representation of quality based on manufacturing exactness and high standards in the silk business.

2. Tussar Silk

Tussar silk or Kosa silk is a variety of silk that is produced from silkworms (mainly Antheraea mylitta) which are a kind of silkworm larvae. Tussar silk is gold for its unique texture, natural shine, and bewitching beauty.

Tussar silk is regarded for its rough touch and a little bumpy lifestyle. Tussar silk has a more uneven texture than silk fabric, which creates a rustic look that is unlike the shiny as well as smooth finish of ordinary silk. Tussar silk fiber is recognized for its strength and makes Tussar silk garments hardwearing and long-lasting.

Tussar silk quality is dependent upon several aspects such as the silkworm diet, the environmental conditions, and the skill of the weavers. Tussar silk is commonly esteemed for its natural gold and beige colors, sheathing the fabric with a sunny and grounded tone. The irregularities in the texture and color make it more likable and different from other types of silks.

The price of Tussar silk depends on many things such as the silk quality, the workmanship, and the place where the silk is made. Tussar silk has become widely chosen for different items as it is cheaper than Mulberry silk and has its own pattern.

The uniqueness of Tussar silk is its natural and woody character. The rougher texture and the irregularities which are natural to the fabric add to its uniqueness. Many people choose Tussar silk for traditional and ethnic wear since it showcases subdued and earthly hues having the best adhesive properties. It is mainly used for home decoration, which has a glossy and wavy texture that makes it a perfect addition to interior designs.

3. Chiffon Silk

Chiffon silk is a delicate and lightweight fabric that is well-known for its sheerness and transparent look. It is beautifully woven from fine twisted yarns. They are made of silk or synthetic yarns such as polyester. Chiffon silk has a characteristic of beautiful mounting and a mystic touch that makes it much preferred for flow and gorgeous dresses.

Chiffon silk possesses a slightly small stretch and its typical crispy characteristic which are illustrated by its faint sheen and smooth touch. Due to its good weave, the fabric is slightly grained which makes it more visually appealing. Chiffon has been preferred for a long time because of the way it creates floating beauty in clothing, mostly evening gowns, brides, and scarves.

It is the quality of chiffon silk that depends on the factors like thread count, fiber quality, and the tightness of the weave. The top-quality chiffon often has a finer texture, better draping capability, and an increased capacity to reflect and refract light, bestowing it with a sophisticated look.

Chiffon silk is a quite posh fabric and its price is determined by such factors as the quality of the silk fibers used, the brand, or any other embellishments and treatments applied. The real silk chiffon is more costly than the mixes or synthetics on the market.

What gives chiffon silk its identity from all other kinds of silk is its weight and transparency. In contrast to bulky fabrics like satin and crepe, chiffon is incredibly light, enabling the highly desirable ethereal and flowing look. Incorporating this material into the garments heightens their elegance, bringing out more of a stylish look with the transparency as an added layer.

4. Crepe de Chine

Crepe de Chine, a celebrated silk family member, is a wonderful fabric famous for its unique feel and elegant fall. It was called Crepe de Chine by the French, but it is rather famous for its unique weaving process. The result is a rough but textured fabric.

The Crepe de Chine boasts of a shiny and lustrous appearance as well smooth and silky texture which is in contrast to that of other silk fiber types. Its lightness as an attribute comes into play too, giving it an edge in fabrics meant to be used in situations that require freedom of movement. Crepe de Chine, not only drapes gracefully but has a subtle sheen that accentuates its elegant and ageless appearance.

The quality of Crepe de Chine depends on the fineness of the silken fibers, the tightness of the weave, and the craftsmanship demonstrated in the whole process. Finer or higher quality Crepe de Chine mostly consists of a smoother fabric texture, better durability, and a capability to enhance its original drape ability with time.

Crepe de Chine is a high-end silk and its high price indicates the quality and lusciousness of the fabric. The price differs depending on the silk breed, the way it is made, and any additional effects that might be added to it.

Crepe de Chine is unique among other silk because it has a curly texture. The crepe effect of Crepe de Chine adds refinement and an appealing look to that silk, making it a sought-after silk for flowy, beautiful clothing like scarves, blouses, and gowns although other silks are smoother and more uniform in their texture.

5. Habutai Silk

Habutai silk, known as "China silk," is a silky and fine material spun from the silk cocoon of the Bombyx mori silkworm. The name this fabric carries is "Habutai" which has origins in Japan and means "feather-two-layer" emphasizing its soft and tender texture.

Habutai silk is famous for its outstanding features of the soft, silky feeling against the body so it has been used for many years for the construction of fabrics for expensive and luxurious clothes. Habutai silk has a very subtle gloss which adds to its overall beauty. The quality of Habutai is defined by its lightness, airiness, and breathability, resulting in its suitability for different climates.

The embodied value of Habutai silk is usually determined according to the number of threads and weave density. Good Habutai silk has a narrow weave and even texture that allows tearing and gives the fabric a high-end look. Its flat structure is responsible for the show of saturated and high gloss colors.

The price for Habutai silk fluctuates in light of the grade of silk, the density of weave, as well as any further treatments or embellishments. Habutai silk is considered to be less expensive than other kinds of silk, hence, it is an alternative for individuals who want elegance but without paying a high premium.

What distinguishes Habutai silk from other silk types is its bird-like weight and soft falls. Silk is frequently used fabric for making flowing garments such as tops, dresses, and shawls. Habutai's versatility lies in its being a suitable lining material for jackets and bridal gowns because of its smooth finish that feels so nice to touch.

6. Organza Silk

Organza silk is a sheer and lightweight fabric that has an ethereal look and is described as a material with a delicate texture. Organza silk has gained recognition because of its distinctive features and wide application out of silk fibers.

Transparent and with a crisp smooth finish is what organza silk is known. The fabric has a fine plain weave, and its lightness helps it to be draped beautifully. Organza is a mixture of silk and synthetic fibers woven to add power to it while retaining the shine. The fabric's surface has a subtle, well-balanced shine that gives any garment or design a tint of subtle sophistication.

Organza silk is marked by attributes such as silk purity, weave density, and excellence of craftsmanship amongst others. Higher-grade organza is very smooth and glossy, and the weave is finer and gives a feeling of sumptuousness and look.

The cost of organza silk relies on the sort and grade of silk used, the intricacy of the weave, and the brand. Organza silk, in general, is considered a luxury fabric and hence, more costly than the other silks. Yet, its outstanding features outline it as a preferred for elegance and high fashion accessories.

Organza silk is very special because, in addition to its being sheer, it is versatile. It sheds transparency, which is used for art and even fashion or interior design. Organza is sought for wedding gowns, evening wear, and accessories as it gives glamour without being too heavy. Its sharp finish allows it to be used in the creation of intricate details such as ruffles, bows, or overlays.

7. Dupioni Silk

Dupioni silk, known as Dupion or Dupioni, is a type of silk with a distinctive texture and an attractive appearance. Duppioni silk, as the name suggests, is tied to two cocoons weaving together. Through the unevenness and slubbiness, a unique surface is created that is associated with silk's characteristics and fascination.

This type of silk is known for its crisp drape and subtle sheen, which make it suitable for those who prefer a slightly nubby texture that is different from smooth silk varieties. The imperfections in the print achieve a unique, natural effect, and thus every item is a custom one. Dupioni silk enjoys a reputation for adaptability as it is combined with traditional and innovative patterns that are alike.

Dupioni silk quality often depends on factors like fiber thickness, uniformity of threads, and the absence or presence of any defects. It is characteristic of the higher-quality Dupioni to have a more elegant appearance with fewer slubs, which creates the impression of smoothness and silkiness.

Dupioni silk is usually priced in the mid to high range. The price ranges from one product to another depending on the silk's quality, color, and any other decorations or treatments made to it.

Dupioni silk is different from the other silks because its surface is structured by two cocoons that are merged to make one another. The textured surface creates a visual interest and provides a slightly coarse touch compared to silk which comes in smoother varieties. The unevenness of the textile adds to the authentic and cozy appeal, so Dupioni silk is used in bridal gowns, evening gowns, and home decor.

8. Georgette Silk

Georgette silk is a softly crinkled material, which is very light and thin with graceful nobility. The yarn of Georgette silk is tightly twisted, most often in plain or satin weave, so the result is a textured surface like a pebble. The fabric derives its name from the French fashion designer Georgette de la Plante of the early 20th century who was famous for using these fabrics in her work.

Georgette silk enjoys a high reputation due to its lightness and airiness that favor its use for the creation of fashionable and flowing outfits. The drape surface, with its crumbled surface, is ethereal, thus offering visual interest and texture. A Georgette silk is suitable for many different fashion purposes for it drapes beautifully and has strength even though it looks delicate.

Thread count, yarn twist, and overall weaving job are typical principles that provide a clue on Georgette silk quality. A fabric of high-grade Georgette silk is finer, softer, and more durable compared to the lower-grade fabric. Superior Georgette fabric is carefully made providing a solid and uniform structure that emphasizes the softness of the fabric.

Georgette silk is by and large the finest fabric and the cost of it changes due to the quality of silk, the sophistication of the weave, and any silk treatment or embellishments. High-quality silk Georgette is usually more expensive since the production process is labor-intensive and materials of high quality are involved.

The quality of the Georgette silk differs from other silk varieties by its crinkled texture. It looks improved and very deep. Georgette silk is an admired fabric for large garments such as flowing dresses, formal wear, and bridal gowns, due to its unique appearance. It is worn in professional and casual environments, so it proves to be a staple in upscale fashion due to its flexibility.

9. Raw Silk (Dupion)

Dupion or raw silk is unique and stands out from other forms of silk. The unique construction method which results in a slightly rough and uneven manner complements its character.

Raw silk is woven from uneven and thicker fibers, creating a charming, natural look characterized by a slightly slubby texture and crisp feel. The unevenness of the weave provides a natural feeling and has a visually appealing texture, reminding of old folk art with its rustic and authentic look.

Silk's raw quality is usually connected with faults of its own, in common with the appearance of slubs and thickness variations which are even considered attractive flaws. The natural roughness and unpolished state offer the garment a classic appeal, suitable for those who are looking for something unique and a bit textured.

Raw Silk is not as pricy as its polished and smooth brothers on occasion, but that does not take anything away from the products' remarkable variety and customer-friendly prices. The prices vary as they are affected by the source, how the fabric was woven, and the general quality of the fabric.

The texture and appearance of Raw Silk bring it to the fore among other types of silk. The appearance of slubbing of raw silk provides a striking contrast to the slick and shiny finish of conventional silk making it look more natural as well as earthy. Raw silk stands out among the other materials for different items of apparel, like casual clothes, wedding dresses, and home furnishings, where its unique texture adds a hint of personal character to it.

10. Matka Silk

Matka silk, known as Katia silk, is an exclusive type of silk that is distinguished by its special touch and earthy beauty. Matka silk is usually woven by hand, therefore, it is a part of the artisanal origin of this region of the Indian subcontinent.

Matka silk has a characteristic of a coarse texture and a little bumpy surface. The unevenness of weave construction is responsible for creating a natural and raw design making every piece of Matka unique. The slub of Matka silk is slightly rough and is something that lends it this rugged and natural texture.

The Matka silk is valued for its authenticity, unlike machine-made products. The distinctive character of Matka silk is enriched by its presence of roughness and imperfections which if not so smooth compared to other silk types are generally regarded as attractive features.

The prices of Matka silk depend on variables like silk fiber quality, design elaborateness, embellishment, or dyeing techniques. Matka silk is regarded as a mid-range option in terms of price for individuals to choose some premium silk varieties without the high cost is a good thing.

The main difference between Matka silk and other kinds of silk lies in its natural and undone effect. Its irregular weave along with the slubby texture make it one of the unique and handmade textiles. It is a versatile and useful technique that is found in textile designing to enhance the aesthetic appeal of garments, home textiles, and other fabric products. The silk known as Matka drapes well so it is used in different clothing and accessories while being adaptable enough.

What Is Silk Fabric?

Silk fabric is a natural textile that comes from the silkworms' fibers usually extracted from the cocoons of Bombyx mori species. It is highly valued and firmly established in the textile industry because of its super-elite properties and remarkable characteristics.

The silk fabric in textiles is irreplaceable because of this unique combination of softness, shininess, and sturdiness. Silk fabric has been loved for thousands of years for its soft texture and rich feel, a symbol of nobility and wealth. The multipurpose of silk enables its use in different forms from high-quality clothes to beautiful accessories and home textiles. Silk’s popularity persists due to its ability to provide comfort and sophistication.

How Is Silk Fabric Made?

Silk fabric is made by following the steps below.

1. Silkworm Rearing. Silkworm Farming first involves the growth of silkworms, specifically of the Bombyx mori species. Bombyx mori silkworms are larvae that are raised in enclosed locations with the specificity to eat only mulberry leaves for superior silk quality.
2. Cocoon Formation. Cocoon Formation is a process by which silkworms spin protective cocoons around themselves using a liquid they can secrete. The flow liquefies into silk threads once it hits the wind. Spinning lasts several days. Throughout this process, the silkworms build a hard, dense cocoon.
3. Harvesting. Harvesting means very detailed picking of the cocoon once it is done. The traditional method involves boiling the cocoons to soften the sericin, which is a protein that binds the silk fibers together. The eggs, larvae, and pupa boil inside.
4. Reeling. The process of reeling happens when cutting the silk strands from the softening cocoons. It is done carefully by removing or unrolling the silk filament, which is often longer than a few hundred meters.
5. Twisting and Spinning. Twisting and Spinning is the process that is involved in twisting the individual silk filaments to form one thread. The twisting process increases the strength and durability of the silk fibers. The entangled threads are spun into yarns, the components from which the fabric is made.
6. Weaving or Knitting. The yarns are used in weaving or knitting by passing them through looms or knitting them together. Different weaving methods are used to make various kinds of silk cloth with diverse textures and images.
7. Dyeing and Finishing. Dyeing and Finishing come after the fabric is woven or knitted, as it undergoes dyeing to achieve the desired color. Various finishing processes, such as degumming (removing excess sericin), softening, and polishing, follow to enhance the fabric's texture and appearance.
8. Cutting and Sewing. Cutting and Sewing mark the final steps in the process, where the silk fabric is cut into the desired patterns and sewn together to create finished products, such as clothing, accessories, or home textiles.

What Are The Uses Of Silk Fabric?

The uses of silk fabric are listed below. 

• Fashion Industry: Silk is widely used by fashion firms because it adds an element of luxury and elegance to the celebrity racks. Silk is widely used for making high-end and smooth silk clothes, because of its silky and smooth texture. Silk is found in suits as well as in the more luxurious dresses, where its smooth texture gives an air of elegance and improves comfort. The fact that silk is highly breathable is the feature that makes this type of material perfect for the lingerie, therefore the lingerie that has a combination of being comfortable and sexy at the same time is created.
• Textile Industry: Silk is the material that certainly strikes a chord in the textile business where it is used for many applications owing to its shine and adaptability. Silk's satin-like look is the perfect match for scarves and ties as it makes them shine. Silk is seen further on face adornments and used as bedsheets and pillows that offer an incredibly smooth experience. The use of silky fabric for drapes and curtains gives the room a special look and at the same time, it makes it more appealing.
• Traditional Attire: Culture around the world has cast silk as an important traditional dress material. Silk sarees are considered eternal symbols of variety in countries like India, where they are traditionally worn at important functions and celebrations. In Japan, different types of silk are used to weave kimonos, and the result is to make an individual feel luxurious. 
• Wedding Attire: Silk's prestigious image radiates in the fashion of the wedding where it is a preferred material for designing unique wedding dresses. Its rich texture and deep luster create the perfect playground for detailed patterns, resulting in the creation of dresses that represent tradition and modern-day sophistication.
• Accessories: Silk silk embellish the accessories. High-class wrist bags are renowned for applying silk as a showing material in bringing about the fashion accessory's elegance and refinement. Silk fabric is creatively used for making fashionable hair accessories silk shows its application in the crafting of hair accessories.
• Athletic Wear: Silk has gained popularity in the area of sportswear because of its ability to regulate temperature and absorb moisture. Combined with other materials, silk switches on base layers comfort and performance, and creates a unique feeling even during most active pursuits.
• Home Textiles: Silk is used for personal life and home textiles. In upholstery, silk is on rare occasions used to get that luxurious and classy touch to the furniture. Silk woven pillows, made into accessories with a soft texture and unique beauty, are the highlights of the interior decoration, adding a hint of luxury and class to the living space.
• Art and Craft: Silk fabric, which goes beyond its utilitarian function, has its space in the world of art and craft. The flatness of the fabric turns it into a blank canvas for skillful paintings and complex embroidery, enabling it to unleash creativity.
• Medical Applications: Silk's biocompatibility is a historical medical record of its biodegradability. Silk has been utilized in surgical sutures which highlights its efficiency in medical care.
• Industrial Uses: Silk offers transparent thin fibers with remarkable strength that are utilized in optical systems providing them a distinctive dimension.

What Are The Benefits Of Silk Fabric?

The benefits of silk fabric are listed below.

• Luxurious Comfort: Silk is celebrated for its unparalleled comfort, providing a luxurious and smooth feel against the skin. Silk’s soft and supple nature adds a touch of opulence to clothing and bedding, creating an indulgent experience.
• Natural Breathability: One of the inherent advantages of silk is its natural breathability. Silk allows air to circulate, regulating temperature and keeping the wearer cool in warm conditions. Silk’s breathable quality makes silk an excellent choice for various apparel items.
• Hypoallergenic Properties: Silk possesses hypoallergenic properties, making it a gentle option for individuals with sensitive skin or allergies. Silk’s smooth texture and lack of irritating substances contribute to a comfortable and irritation-free experience.
• Gentle on Hair and Skin: Silk is gentle on hair and skin, unlike some other fabrics. The smooth surface of silk minimizes friction, reducing the risk of hair breakage and split ends. Silk's soft touch is kind to the skin, making it an ideal choice for sleepwear.
• Durability and Longevity: Silk is a durable material despite its delicate appearance. Silk clothing resists wear and washing if properly cared for, preserving its quality and beauty for a long time. The lifetime of silk goods is influenced by durability.
• Natural Sheen and Elegance: Silk is renowned for its natural sheen, lending an inherent elegance to anything crafted from silk. The way silk reflects light adds a touch of sophistication to clothing, accessories, and home textiles, making it a preferred choice for individuals seeking a refined aesthetic.

What Are The Downsides of Silk Fabric?

The downsides of silk fabric are listed below. 

• Cost and Accessibility: The natural elegance of silk, which comes at a cost, means it is more expensive per unit than other fabrics. The pricing factor makes the product less diverse for other consumers.
• Delicate Nature: Silk's delicacy is a downside in that it is more easily damaged by abrasion, pulling, or cutting than many other fabrics. Such softness is more fragile during use.
• Susceptibility to Stains: The problem with silk is that it gets stained easily, and the removal of stains is difficult. Stains or marks have a long-lasting impact on the fabric structure.
• Specialized Care Requirements: Silk requires extra work when it comes to cleaning and maintenance. Dry cleaning or handwashing with mild detergents is usually recommended, adding the necessity of producing a very careful and costly preservation.
• Environmental Considerations: Silk production concerns some environmental aspects such as mulberry tree cultivation, silkworm food, and energy-consuming processing.
• Limited Stretch and Elasticity: The level of stretch and elasticity of silk fiber is low when compared with some of the synthetic materials. It stops silk from being applied in the places where there should be a stretch.

What Are The Tips For Maintaining Silk Fabric?

Some tips for maintaining silk fabric are listed below. 

• Handwashing Technique: Hand wash silk fabric softly as an alternative to machine wash if wished to preserve it and prevent damage.
• Use of Mild Detergents: Opt for gentle detergents formulated for silk to ensure such fabrics remain in good condition while still being thoroughly clean.
• Cold Water Rinse: Always rinse silk in cold water to keep its natural gloss and avoid the chance of shrinking.
• Avoiding Direct Sunlight: Preserve silk from direct sunlight which causes the color bleeding and eventually makes the fabric duller.
• Air Drying: Dry the silk in the air by placing it flat on a clean and dry towel to avert possible damage when subjected to heat or harsh drying methods.
• Steam Ironing: Work with a steam iron on low to get rid of wrinkles on silk but be careful to avoid too much heat.
• Storing with Care: Make sure to keep silk items in a substantially cool and humid place with vented garment bags to prevent them from getting destroyed by moisture.
• Avoiding Perfumes and Deodorants: Avoid contact with perfumes and deodorants during silk use as they are mostly made up of chemicals that ruin the fabric.

Where Is Silk Fabric Produced?

Silk fabric is produced in countries with a long heritage of sericulture and the process of mulberry leaves feeding silkworms to silk production. China is the largest silk producer in the world and its contribution to global silk output is high Other important silk-producing countries include India, with its long-established silk culture, as well as countries such as Brazil, Thailand, and Vietnam. Italy and Japan have a reputation for being the best silk producers who usually manufacture silk cloth for superior fashion. The manufacture of silk fabric is governed by the presence of mulberry trees, suitable climatic conditions, and historical traditions in such regions.

What is the Average Cost of Silk Fabric?

The price of silk cloth is determined by different factors like the kind of silk, its overall quality, weave, and the place of production. The silk is treated as a luxury and high-price goods and its price is set correspondingly. The average price spread on silk fabric being from $15 to $200 or even more a yard is caused by the yearly varying demand and cost as well as the quality and type of the silk.

This is because rough silk or low-quality silk is among the lowest-priced silk products, while the highest-quality, very finely woven silk or special silk, such as mulberry silk, is the most expensive. Designer or specialty silk fabrics are more expensive.

What is the Cultural and Economic Impact of Silk Fabric?

The cultural and economic impact of the silk fabric hangs great weight in different societies, which is a symbol of luxury and refinement. Chinese and Indian sericulture and silk weaving are very ancient with the world of silk being woven deep into their way of life. Silk was born in China, in its homeland, and was the discovery of Empress Leizu giving a mythological aspect to its cultural narrative. Silk has already established itself in the traditional clothes industry, the Chinese cheongsam and Indian silk saree are examples of such garments that symbolize elegance and tradition. The silks with their elaborate designs and vivid colors frequently have a special cultural meaning, having stories and symbols that reflect the arts of the place.

The economic importance of silk production to international trade cannot be underestimated. China is still a giant player in the silk industry, where silk export plays a major role in the national economy. Historically the Silk Road connecting East to West was involved in the trade of silk besides other items, which affected the economic situation of the countries and promoted cultural diversity. The silk demand remains high around the world where it is used in trade by lots of countries. The economic impact of the silk trade is not restricted to countries that manufacture silk. They help individuals involved in trade, processing, and selling which translates into job creation and economic growth.