Fabric 101: Silk

While many people automatically think of silk as being a lightweight, shiny, satin and succulent material, it can actually be used to make many different types of fabric. Silk is the fiber that is used to create the different fabrics and it can be woven into just about any kind of fabric, from a sheer silk chiffon to a much heavier silk faille that can be used for coating. 

Even though the materials silk is used for can be quite different from each other, the silk fibers themselves have certain qualities that can extend to the materials it’s woven into. From having a subtle sheen to having a natural breathability, there are certain basic characteristics that you can expect from any type of silk fabric.

What is silk fabric?

Silk is probably the most expensive and luxurious type of fiber. It is an animal byproduct that’s extracted from the cocoons of silkworms (usually the larvae of the Bombyx mori moth). Silk production is a meticulous process, where the silkworm’s cocoons are harvested and woven into silk fabric.

The resulting fabric is durable (except when wet), soft, smooth, and has a delicate sheen to the surface. Due to these characteristics, silk has historically been associated with luxury. Even to this day, silk is quite expensive and is typically only used in high-end fashion.

Most of the fabrics with a silky appearance that are seen in everyday clothing are actually silk mimics. These are made from synthetic fibers, such as polyester or rayon, and tend to lack many of the more subtle characteristics of true silk fabric.

Properties of silk

Real silk is a natural fiber with characteristics that synthetic fibers struggle to imitate. These are the main qualities of real silk you can expect regardless of the type of weave or material it is. 

• Texture: Silk is renowned for its smooth and soft texture. Unlike synthetic fabrics, silk doesn’t feel slick or plastic-like, making it much more comfortable to wear.
• Weight: Typically, silk fibers are used for lightweight fabrics. Silk fibers can be woven into heavier materials, suitable for a range of uses from evening wear to upholstery.
• Drape: In most cases, silk naturally flows and contours gracefully. However, not all silk materials conform to this fluidity. Some types of silk materials (such as dupioni, taffeta, and shantung) are known for having a crisp, stiff drape. So it depends entirely on the material at hand and how it’s woven together.
• Sheen: Silk exhibits a natural shimmer that subtly catches the light. It’s a natural-looking glow and is not an over-the-top shine like synthetic fibers that try to mimic silk.
• Good moisture absorption: Silk can absorb moisture, keeping you cool and comfortable even in hot weather. However, the fibers lose their strength when wet so you always need to be very careful when washing silk.
• Silk wrinkles easily: While silk doesn’t generally get deep creases like linen or cotton, it does wrinkle fairly easily. You’ll need to be careful when handling and be sure to store silk garments carefully to keep them in good condition.

What to know before you start sewing with silk

So you bought some silk fabric but now you’re afraid to sew with it. You don’t want to ruin it because of how expensive it is, but, of course, you want to make something and show it off too!

First and foremost, I recommend using a small swatch of the silk fabric to do some tests. This will help make sure you choose the best needle, machine tension, use the right pins, and cutting utensils. You can also test your iron to make sure you won’t accidentally burn the fabric.

Use these tips to help you get started, and sew that gorgeous silk fabric with confidence:

1. Choosing the Right Needle: Microtex needles size 65 or 70 are usually ideal for silk. Their sharp point allows for precise stitching without damaging the fabric.
2. Change the Throat Plate: To prevent the silk fabric from being pulled into the machine (especially with more delicate silk fabrics), it might be worth considering a straight stitch throat plate. It provides a smaller opening, offering better support during stitching. (you want to make sure you purchase a straight stitch throat plate that fits your specific machine at home, since they are not standard size)
3. Stitch Length: When sewing silk, opt for a shorter stitch length, around 2mm, as this will give you a stronger seam suitable for delicate fabrics.
4. Cutting Your Fabric: For cutting silk, especially when it is drapey, use a rotary cutter and a cutting board. This method helps in achieving a clean, non-slip cut more easily than using fabric shears.
5. Ironing Silk: Heat can be silk’s enemy if not moderated. Always use a low to medium heat setting on your iron and ensure to press gently. You can use a pressing cloth as an added layer of protection.
6. Steaming silk: Be wary of water or steam that might spit from the iron or steamer, since this can stain and cause unsightly spots on the silk. 
7. Never bleach silk: Bleaching silk causes it to turn an ugly yellow color, so it’s best to avoid this completely.

I hope these guidelines will help give you the confidence you need to branch into sewing with silk fabric for the first time!

Caring for silk fabric

While individual silk fibers are strong, the fabric made from them tends to be delicate, especially when wet. To keep your silk garments in good condition for a long time, you will need to take some extra steps to care for them.

• Most silk should be dry cleaned or hand washed. The more delicate the fabric, the more you will need to adhere to this. Since silk fibers are weak and prone to ripping when wet, washing silk garments too aggressively can ruin the fabric. Fabrics with a silk blend (instead of 100% silk) may be able to be washed on delicate settings.
• After cleaning, lay the silk flat or hang it up to dry in a shaded area. Avoid prolonged exposure to direct sunlight as it can fade the colors and weaken the fabric.
• If you intend to wash silk by hand (or on the delicate washing machine settings) make sure you preshrink the fabric by washing it before cutting your pattern pieces. This process helps to maintain the fabric’s shape and integrity after subsequent washes. Use whatever settings or washing methods you intend to use on the final garment. If you only intend to dry clean your handmade silk garments, this step is not necessary.
• When using an iron, select the low or medium heat settings to avoid burning the silk. It’s also best to avoid using too much pressure with delicate silk fabrics. Consider ironing on the reverse side or placing a cloth between the iron and the silk to prevent damage.

Common types of silk fabric

While many fabrics are more often made from silk mimics nowadays, there are still plenty of materials that still use this fiber. If you’re looking for some common types of silk fabric that are still in use today, consider one of these options:

• Shantung or Dupioni: two similar fabrics that are stiff and crisp with distinct slubby texture.
• Taffeta:  Known for its smooth, stiff texture and subtle sheen
• Chiffon: This lightweight fabric is sheer and transparent, with a soft, airy drape
• Organza:  Organza is sheer and lightweight like Chiffon, but it possesses a stiffer texture.
• Satin weave fabrics: Satin silk is known for its glossy surface and dull back, popular types of silk satin include Charmeuse and duchess satin.
• China silk: As a lighter and softer variant of silk often used for linings.
• Thai silk: hai silk offers you patterns and colors that are distinct, often used in scarves and traditional garments.
• Silk noil: This is a rougher silk, with a nubby feel and a low sheen
• Tussah silk: Typically made from wild silkworms, Tussah silk presents a coarse, uneven texture with a natural golden color
• Faille: A crisp and subtly ribbed silk that is typically used for more heavyweight silk projects, such as coating or suiting.

Each silk type has its unique characteristics and qualities. Your choice will depend on the texture, sheen, weight, and drape you desire for your project.

Silk and sustainability

Silk isn’t the worst fiber for the environment, especially since it makes up a very small percentage of the fiber marketplace and is not a very scalable operation. However, there are still many environmental and animal welfare concerns about silk fibers that cannot be ignored

On the plus side, silk is a natural fiber that is both renewable and biodegradable, making it a more environmentally friendly option when compared to most synthetic materials. It also possesses a remarkable tensile strength, provided it is well maintained.

Despite these benefits, silk production is still fraught with sustainability concerns. The traditional processes involve high levels of pesticides and water consumption, mostly due to the mulberry trees planted for silkworms’ nutrition. During silk extraction, harmful chemicals for degumming and significant energy use contribute to its environmental impact. Furthermore, wastewater and runoff from these farms can lead to contamination of groundwater and waterways in surrounding areas.

From the perspective of animal welfare, the standard silkworm farming practices involve killing the chrysalis to get the long, continuous silk filaments. Those that are not killed and are instead used for more eggs grow into moths that are  incapable of flying at all due to thousands of years of selective breeding.

Labor practices in the industry may also raise concerns. While there are certainly some silk farms that have good working practices and contribute to the economy of the surrounding communities, silk production is not always associated with ethical working conditions and has been known to involve child labor, making it essential to consider the source of your silk products.

Sourcing sustainable and cruelty free silk

For those looking for more sustainable options, consider sourcing alternatives like wild silk or peace silk. These other types of silk allow the moth to hatch before the fibers are collected so they are not killed in the process. The resulting silk filaments are shorter and rougher than traditional silk, but with a lesser environmental footprint.

To further ensure ethical choices, consider looking for silk that is GOTS certified. By choosing GOTS certified organic silk, consumers can be assured that the silk was ethically and responsibly produced with attention to environmental and social impacts. The certification process involves rigorous criteria, which include the prohibition of harmful chemical inputs, the requirement for sustainable farming practices, and the adherence to social criteria like fair labor conditions. This holistic approach to sustainability ensures that the silk production process helps reduce the environmental footprint and supports the well-being of workers in the textile industry.

Another option is silk noil, also known as raw silk. This is made from the short fibers left after combing and carding, so it doesn’t have the same shine as cultivated silk. It is considered a more sustainable option because it makes use of the entirety of the silk cocoon, reducing waste.