Fabric 101: Denim

Denim is known for being an extremely durable fabric. The material uses a dense twill weave that uses two colors of yarn to create that iconic appearance of denim. The main color will usually be a shade of indigo blue running along the length of the material, while white yarns are used along the width.

Denim is one of the most recognizable types of fabric in our modern world. Everyone is aware of its use in jeans and denim jackets, and could probably pick out a bolt of denim in a wall of fabric. But if you want to use denim for your next sewing project, it’s time to learn a little bit about what exactly denim is and how to sew with it.

Fabric	Denim
Texture?	Textured surface, but not rough to the touch
Stretch?	No stretch unless it contains spandex fibers, in which case it’s called stretch denim
Heavy or light?	Medium to heavy-weight
Stiff or flowy drape?	Stiff drape
Nap?	No nap
Typical fiber content?	Usually made from cotton or a cotton blend
Opaque or sheer?	Opaque fabric
Shiny?	Matte fabric
Fraying?	Expect a standard amount of fraying
Pilling?	Somewhat resistant to pilling
Colors and patterns?	Usually in shades of indigo blue, but it can be made in black, white, and other colors
Other identifying properties?	Denim uses a twill weave where the vertical yarns (warp) are the color of the fabric, and the yarns that go along the width of the fabric (weft) are white
Cool or warm weather?	Typically better for cooler weather, but it’s breathable and can be worn in all weathers
What to make?	Most often used for jeans, heavy-duty pants, and denim jackets, but it can be used for a wide range of apparel and home decor
What needle to use?	Use a heavy-duty or denim needle

What kind of fabric is denim?

Denim is a sturdy and adaptable fabric made from cotton fibers. It uses a diagonal twill weave that makes the fabric quite durable. The sturdiness of denim makes it long-lasting, allowing it to withstand the test of time and last through daily wear and tear.

Denim gets its iconic look from weaving white yarns in with the indigo dyed yarns. The indigo color will be most prominent on the front face, while the white yarns will be more prominent on the back. This is why you’ll notice the inside of jeans or denim clothing is a lighter color than the front.

Additionally, the fabric develops a unique worn-in appearance over time, giving it a distinct character and individuality. Denim can be worn for both work and casual occasions without any difficulty, making it a durable part of anyone’s closet.

Types of denim fabric

Anyone can recognize denim when they see it. However, there are a few different types that you you can run into if you want to explore denim a little further:

• Raw Denim: this is unwashed and untreated denim. It has somewhat of a ‘cult’ following by denim enthusiasts for its ability to develop personalized fading and creasing patterns over time. Note: if you’re working with raw denim, be aware that it will shrink the first couple of times you wash it.
• Stretch Denim: this uses a small percentage of spandex (also called elastane) in the cotton fiber blend. This type of denim offers added flexibility and comfort, making it a little better for tighter jeans. Most store-bought jeans nowadays will have a stretch denim blend.
• Selvedge Denim: Known for its clean, self-finished edges, selvedge denim is associated with premium quality. It is woven using an older traditional shuttle loom, resulting in a narrower fabric width and a distinct, often visible, colored edge.
• Acid Wash Denim: With a vintage-inspired look, acid-wash denim undergoes a chemical treatment to achieve a faded and worn appearance. It was particularly popular in the 1980s and has made a comeback in recent fashion trends.
• Colored Denim: While traditional denim is typically indigo, colored denim encompasses an array of vibrant hues or leaves out the color entirely, giving you white denim. 

What weight of denim should you get?

When you are looking to buy denim fabric, it’s usually labeled with a weight in ounces. This tells you how heavy the denim is which will give you a better idea of what you can use the fabric for. (For a point of reference, the average pair of jeans is going to be about 12oz)

Here are some quick guidelines to help you understand denim fabric weights:

1. Lightweight denim: Typically ranges from 4 oz/yd² to 8 oz/yd². This type of denim is lighter, suitable for warmer climates, or creating more lightweight garments like shirts or dresses. I use this for lightweight summer jeans too.
2. Midweight denim: A commonly used weight for standard, everyday jeans, midweight denim falls around 8 oz/yd² to 12 oz/yd². It strikes a good balance between durability and comfort, suitable for various seasons and styles.
3. Heavyweight denim: Generally found in 14 oz/yd² or more, heavyweight denim is preferred for its durability and ability to withstand heavy use, making it ideal for work jeans or outerwear.

These weight ranges can vary across different denim manufacturers, so something labeled heavyweight may actually be more mediumweight. If the information is available, it’s always helpful to check the specific weight mentioned on the fabric label to have a better idea of how robust your denim fabric will be.

I’ll also mention that a typical sewing machine can usually handle lightweight denim and some mid-weight denim fabrics. However, heavy-weight denim will probably require a more heavy-duty machine that is specifically made to sew through multiple thick layers of fabric

What can you make with denim fabric?

Denim is most well known for its use in jeans, but it’s also common to use denim in overalls, jackets, and outerwear. It’s worth noting that denim fabric is also used in accessories like bags, hats, and even footwear.

Properties of denim fabric

• Texture: Denim is typically somewhat rough and stiff due to the heavy duty twill weave. However, it will become softer over time as you wear and wash the garments, becoming more comfortable and acquiring a broken-in feel.
• Flexibility: Traditional denim made from 100% cotton typically offers minimal stretch and is quite rigid. However, many denim fabrics today incorporate stretch fibers like spandex to enhance comfort and flexibility.
• Weight: Denim is medium to heavyweight. The most common is midweight denim that is used for jeans, and typically ranges from 8 oz/yd² to 12 oz/yd²
• Drape: Denim fabric has a stiff and structured drape, meaning that denim holds its shape when used in garments. Lighter-weight denim may offer a slightly more relaxed and flexible drape, while heavyweight denim will maintain a firmer and more rigid structure.
• Fiber composition: Most denim is made from 100% cotton or cotton with a small amount of spandex to allow for some stretch in the material. However, recently I’ve been finding it more common to see denim made with a cotton and rayon blend, or a cotton and polyester blend as well.
• Opacity: Denim is known for being completely opaque.
• Shine: Denim fabric has a dull matte appearance.
• Fraying: Due to its tightly woven structure and heavier weight, denim is less prone to fraying compared to lighter or looser weaves. It will still fray a bit though, especially when going through the wash cycle. So be sure to finish your seams as you sew your denim garment.
• Durability: Denim is known as being one of the most durable types of fabric there is. This is why your jeans always last so much longer than all the rest of your clothes.
• Wrinkling: Denim fabric is somewhat resistant to wrinkles and creases. Its sturdy and heavyweight nature allows it to maintain its shape well and resist wrinkling even after prolonged wear.
• Color: In denim fabric production, the incorporation of white yarns in one direction with the indigo in the other creates that distinct denim ‘heathered’ color. This process involves weaving white yarns horizontally into the indigo-dyed vertical “warp” yarns to create the characteristic denim look.
• Breathability: Due to its heavier weight and tight weave, denim fabric is not usually very breathable. That being said, lightweight denim blends can be more suitable for warmer weather as they offer improved breathability.

How to sew with denim fabric

While lightweight denim shouldn’t give you too many issues when sewing, medium to heavy-weight denim can be a struggle due to the thickness of the material. In many cases, you will need to have a heavy duty sewing machine that is specifically made to sew through thick, heavy fabrics. (I specifically purchased a Juki F300 because it’s one of the best home sewing machines for handling denim)

However, modern sewing machines can surprise you with what they’re able to do if you use the right tools and settings. 

• Start by using a heavy-duty needle, suitable for denim’s thickness. You can use a needle labeled ‘jeans’ or ‘denim,’ or just find one labeled ‘heavy duty’
• Use a heavy-duty thread. Polyester and nylon tend to work better than cotton thread.
• Use longer stitch lengths. This will help when trying to go through all those thick layers. Short stitches are more likely to cause tangles and jams in the thread.
• Adjust the foot pressure and thread tension. Usually, you will want to decrease the thread tension, but this will come down to the settings of your specific machine.
• Trim any bulky seam allowances, to avoid big bumps on your final garment and make your machine go through fewer layers.
• You’ll also want to pre-wash your denim fabric. Not only will this help avoid shrinkage later on, but it can soften the fabric slightly and make it easier to sew.

More details about how to sew with denim fabric

How to care for denim fabric

To extend the lifespan of your denim, it’s wise to wash it sparingly. Denim typically doesn’t require frequent washing, so opt for spot cleaning or airing it out instead. Avoid using harsh detergents or bleach, as they can weaken the fabric and cause fading. Since denim is typically made from cotton fibers, it can shrink when you use excessive heat. So it’s best to wash it in cold water and use low heat settings on your dryer. 

Denim is also pretty wrinkle-resistant, so you shouldn’t have to iron it very much. But if you do, it can typically stand up to medium or high heat. It’s always a good idea to test the iron on an inconspicuous part first (usually somewhere on the reverse side of the fabric) to make sure it’s not burning the fibers.