The Essential Fabric Guide: From Cotton to Denim – Everything You Need to Know

If you’re starting a clothing line, fabric is the make-or-break factor. No matter how great your designs are, if the fabric is shoddy, loses shape after a few wears, or washes unevenly, you lose your repeat customer. Lots of entrepreneurs devote most of their time to perfecting the silhouette and logo, only to realize that the finished product is a different animal than their sample—or worse, it unravels after the first wash. Here’s the lowdown, from plain cotton to out‑there technical denim, so you make the right call.

1. What Makes a Fabric “Good”?

Consider fabric as the ‘skin’ of your garment. It will impact drape, comfort, durability and value. Rather than judging fabric solely by feel and appearance, industry experts evaluate fabric on five basic aspects:

Hand feel – feels good and soft to the touch but has enough body so it holds its shape. Flimsy fabric communicates cheapness.
Weight – measured in GSM (grams per square meter). The higher the GSM, the thicker and heavier the fabric is, but heavier is not necessarily better (consider season & style).
Dyeing qualities – evenly and intensely coloured, with no streaks, blotches or bleeding. Bad dyeing leads to customer complaints after one wash.
Recovery and extensibility – the fabric should be resilient and recover its shape quickly. Fabrics constructed with elastane should not hang limp.
Shrinkage – industry standard should be less than or equal to 3% after washing. Anything more, and you’re in trouble with your sizing.

Fabric usually represents 40–50% of the total associated manufacturing cost; this is generally the largest expenditure. Proper fabrics can save you from costly refunds, negative reviews and re‑order time.

2. Natural Fibers: Cotton, Linen, Silk, and Wool

Natural fibers have been used for centuries, with both advantages and disadvantages.

Cotton is the number one choice for apparel. It breathes easily, absorbs well, and is soft to the handle. Quality cotton is defined by fiber length (28.5 mm, 3.8–4.5 for nice bolls), strength (28–32 g/tex), and maturity (Micronaire value). Less than 8% short fiber content (SFC) means high quality. In cotton, you have:

Basic cotton – cheaper and more commonly available.
Organic cotton – chemical‑free, with organic pesticides, certified GOTS. It’s a more eco‑friendly alternative and better for sensitive skin as well.
Long‑staple cotton (such as Egyptian or Supima) – extra‑long fibers give a finer, softer, stronger fabric. Best used in luxury T‑shirts and shirts.

Cotton is used in T‑shirts, shirts, jeans, sweatshirts and underwear. It is the safest and most versatile starting point for startups.

Linen comes from the flax plant; it has the greatest breathability of any fabric and looks lovely and natural with its nubby feel. Ideal for lightweight shirts or casual trousers. Cons: creases drastically and initially can feel a bit stiff, but becomes soft with wear. Suitable for brands with a relaxed resort‑style feel.

Silk is a glamorous fiber with a beautiful sheen and soft handle. It drapes well but is costly, fragile and generally dry‑clean only. Use sparingly for special‑occasion blouses, dresses or scarves.

Wool (merino, cashmere and lambswool) is excellent at retaining heat, so it’s used in a lot of winter wear—coats, sweaters and suits. Wool is prone to shrinkage and can be itchy. Blends that include synthetics improve strength and durability.

3. Synthetic Fibers and Blends

They were developed as alternatives to natural fibers to address issues like wrinkling, shrinking, and lack of stretch.

Polyester is durable, wrinkle‑resistant, quick‑drying and also does a good job of holding onto colour. The downside is that polyester is very poor at breathability, which is why it is nearly always used in a blend with cotton. A typical blend ratio is 65/35 polyester/cotton—known as “65/35”—which gives you the best of both worlds: the comfort of cotton combined with the less‑prone‑to‑wrinkling and quicker‑drying qualities of polyester. CVC (Chief Value Cotton, e.g. 60% cotton / 40% polyester) is closer to the hand of cotton, but with some synthetic benefits.

Nylon is more abrasion‑resistant and even more durable than polyester. It is found in activewear, outerwear and luggage. For performance apparel, use nylon as a foundation.

Spandex (also called Lycra or elastane) is the key to stretch. 2–5% in a fabric adds stretch without any obvious difference in appearance. It is the component of choice in tight‑fitting jeans, athletic wear and any other items that need to be flexible.

Common blends you’ll encounter:

100% cotton – old‑school denim, standard T‑shirts.
80/20 polyester/cotton – hard‑wearing work shirts.
CVC 60/40 – polos, sweatshirts, casual wear.
98% cotton + 2% spandex – stretch denim.
50/50 cotton/polyester – very cheap T‑shirts, with some shrinkage (around 4–5%) on them too.

4. Denim: From Cotton Yarn to Finished Fabric

Denim is a unique fabric: twill‑woven cotton with dye in the warp. Its character derives from the spinning, dyeing and finishing.

Spinning technology affects texture and fade:

Ring‑spun yarn – twisted from the fibers very tightly. It is very durable (15–18 cN/tex tensile), smooth and soft. Since indigo dye can only enter the outer layer of the fabric, ring‑spun denim has that fantastic “ring‑dye” aging, fading to white in high‑wear areas—just like denim fans want.
Open‑end (OE) yarn – produced by spinning fibers at high speed (130–200 m/min). It is coarser, cheaper, and takes in dye more quickly, so the colour is more even and has softer, more subtle fade—ideal for more affordable denim fabrics.
Slub yarn – achieved by changing the spinning speed, thus irregular thick‑thin effects are created intentionally. It looks a bit rough, retro‑style, and is a feature of high‑end “raw” or “selvedge” denim.

Indigo dyeing is a chemical process because indigo is not water‑soluble. It needs to be reduced to a water‑soluble yellow‑green indigo (leuco indigo), imparted onto the yarn, and oxidized back again to insoluble blue on the fiber surface. The pH to achieve this is 11.5–13.0. Rope dyeing (bundling hundreds of warp yarns together) gives uniform colour with little centre‑to‑centre variation.

Denim weight is specified in oz/yd², and you should select according to your desired result and time of year.

Lightweight (6–10 oz) – soft, breathable, perfect for summer, women’s or loose fits.
Midweight (10–12 oz) – the jack‑of‑all‑trades. Works for the majority of jeans, jackets and shirts.
Heavyweight (12–14 oz) – stiff and has a lot of body. Good for workwear, high‑waisted, straight‑leg jeans and recreations of vintage items.
Super heavyweight (14 oz+) – extremely stiff and requires some time to break in. Maintains a specific crease and fades well for those into the raw denim effect.

Dyeing methods include indigo, sulfur, or overdye of indigo and sulfur for a two‑tone effect.

The amount of spandex in stretch denim is 2–5%. It does not show the stretch. The core‑spun method wraps a cotton sheath around an elastane centre to hide the stretch. Select:

Low stretch (1–2%) – for subtle comfort.
Medium stretch (2–3%) – everyday range of motion.
High stretch (3–5%) – hugs tightly to the body.

5. Fabric Recommendations by Garment Type

Here’s a practical cheat sheet:

T‑shirts – find 180–220 GSM cotton jersey. For better quality, go for 200+ GSM long‑staple cotton, which has a more luxurious feel. Streetwear brands often opt for 220–250 GSM for a weighty, voluminous drape.
Sweatshirts – fleece (brushed or unbrushed) 280–380 GSM. Go 380+ for a chunkier, oversized streetwear style; brushed inside adds some insulation.
Jeans – 12 oz midweight is the most versatile. For slimmer cuts, stretch denim (98/2 cotton/spandex) is best. Select 14 oz+ raw if you are appealing to the denim veteran.
Shirts – woven cotton with GSM 100–140. Cotton‑linen blends create a more casual summer feel.
Jackets – canvas or twill should start at 300 GSM. For outerwear, look at water‑resistant or windproof coatings.

6. Common Fabric Mistakes and How to Avoid Them

Mistake #1 – “Heavier GSM is always better.”
Not true. A 300 GSM T‑shirt feels heavy, but in summer you’d be suffering. Choose the right weight for the time of year, the climate and the cut.

Mistake #2 – “100% cotton is the way to go.”
Cotton itself shrinks and wrinkles. For jeans and knits, 2% spandex improves recovery and performance. For shirts, a cotton‑polyester blend keeps the garment looking good.

Mistake #3 – “Imported selvedge is always worth the cost.”
Imported selvedge is tempting, but the best Chinese denim—particularly from well‑known mills—offers comparable value. For startups, Chinese fabric typically is over 80% as good as American or Japanese at only half the price.

Mistake #4 – “We’ll use the same sample fabric for production.”
Samples are manufactured in perfect conditions. Bulk production can vary slightly in colour, shrinkage, and weight. Always require AQL inspections and test washing before cutting.

Final Thoughts and How We Can Help

A fabric does not fit everyone; there is one for each brand personality, target customer and price point. Define your aesthetic (simple, rough, athletic, etc.) and work backwards.

Still got questions or just want to check out some options? Feel free to come by and visit us. Dongguan Jiuzuo Clothing Co., Ltd is based in the centre of China’s denim manufacturing capital in Humen, Dongguan. Our team of over 30 specialists with 10+ years of denim experience is able to produce your jeans completely in‑house—from pattern‑making, layout, cutting through to sewing, washes and QC. We are capable of producing well over 100 000 pairs per month, and our fabric lab is able to perform shrinkage, tensile and colour fastness tests to help you achieve the perfect spec. We’re ready to turn your dream into reality.