Synthetic fibres are made from oil-based chemicals. They are strong, cheap to care for and hold their shape, which is why georgettes, chiffons, nets, satins and linings are so often polyester. This lesson shows what they do well, where they fail in Indian heat, and how blends change the picture.
What you’ll learn
- The main synthetics: polyester, nylon, acrylic and elastane.
- Why synthetics feel hot, and when that does not matter.
- How stretch fibres change fit and sewing.
- How to read a blend: what each percentage brings.
The main synthetics
| Fibre | Strengths | Weaknesses | You see it in |
|---|---|---|---|
| Polyester | Strong, crease-resistant, quick-dry, cheap | Holds sweat and smell, static, melts | Georgette, chiffon, satin, crepe, linings, uniforms |
| Nylon (polyamide) | Very strong, elastic, smooth | Hot, yellows in sun, melts | Net, tulle, lace, innerwear, sportswear |
| Acrylic | Light, warm, wool-like | Pills, static, burns fast | Sweaters, shawls, knitting yarn |
| Elastane | Stretches several times its length and recovers | Damaged by heat and chlorine; ages | Stretch blouses, jeggings, sportswear |
Elastane is also called spandex, or by the brand name Lycra. Shops say “lycra” for almost any stretch fabric.
Why synthetics feel hot
Polyester and nylon absorb almost no water. Sweat stays on the skin instead of soaking into the cloth, so the fabric feels sticky in heat and humidity. In Bengaluru’s mild weather a polyester georgette saree for an evening is fine. For a long summer day in Chennai or a crowded wedding hall, it is uncomfortable. A cotton lining under a synthetic outer layer is the usual answer.
Safety: synthetics and flame
Synthetics melt when they burn, and molten fabric sticks to skin. Around diyas, havans and Deepavali crackers, cotton and silk are safer choices, especially for children. Module 6 returns to this.
Reading a blend
A blend leans towards its larger fibre. Typical Indian blends:
- Poly-cotton (terry-cotton) – cotton’s comfort with polyester’s strength and easy ironing; school uniforms and shirts.
- Poly-viscose (terry-wool, terry-rayon) – smart, cheaper suiting that drapes well.
- Cotton-elastane (2–5 % elastane) – comfortable stretch for blouses, trousers and jeans.
- Cotton-silk – a soft sheen, easier than pure silk (Module 3).
- Silk-polyester – some “semi silk” sarees; lighter and cheaper, but less breathable.
In more depth: stretch and how to measure it
Stretch can come from the knit (Module 2), from elastane in the yarn, or both. To measure it, mark 10 cm along the fabric, hold one mark and gently stretch to the point it starts to resist. If 10 cm becomes 12.5 cm, it has 25 % stretch. Let go: good stretch fabric returns to 10 cm. If it stays longer, its recovery is poor and the garment will bag at knees, elbows and seat.
- Two-way stretch: stretches in one direction (usually across).
- Four-way stretch: stretches both ways; for leggings, dancewear and swimwear.
Patterns for stretch fabric need less ease, sometimes negative ease. A stretch blouse cut from a woven pattern will look loose.
Microfibre and recycled polyester
Microfibre is very fine synthetic filament, used for soft “peach skin” fabrics and cleaning cloths. Recycled polyester is made from used bottles or textile waste; it behaves like ordinary polyester.
Tips, tricks and hacks
- Lower the iron. Start at the synthetic setting and test on a scrap. A shiny mark means too hot.
- Use polyester thread with polyester fabric; it stretches and washes the same.
- Use a ballpoint or stretch needle for elastane blends to avoid skipped stitches.
- Fight static with a cotton lining or a little fabric softener.
- Keep heat away from elastane: no hot dryer, no very hot iron, or the stretch dies.
- Wash sweat out quickly. Polyester holds body odour if left unwashed.
Common misunderstandings
“Polyester is always cheap-looking.”
Good polyester georgette, crepe and satin can look excellent and are the base of many designer sarees and gowns.
“A little elastane doesn’t matter.”
Even 2–3 % changes the fit and the pattern you need.
“Synthetics don’t shrink.”
They rarely shrink in water, but they can shrink or pucker with high heat.
For earning and teaching
For earning: stretch blouses and fitted kurtis are popular. Learn the stretch test and adjust ease so the first fitting is close.
For teaching: a burn test of cotton against polyester (with care) is the single most convincing demonstration of the difference between fibre families.
Problems and how to fix them
Skipped stitches on stretch fabric
- Change to a new stretch or ballpoint needle.
- Use polyester thread.
- Prevention: match needle to fabric before you start.
The fabric melted under the iron
- Cut out the damage if it is in a seam allowance.
- Cover with a design detail if not.
- Prevention: test-press a scrap at low heat.
Static makes the skirt cling
- Add a cotton or viscose lining.
- Use fabric softener in the wash.
- Prevention: choose a breathable lining for synthetic outers.
Stretch blouse is loose at the first fitting
- Take in side and back seams.
- Reduce ease in the pattern for next time.
- Prevention: measure stretch first and use a stretch pattern.
Synthetics by garment
- Party sarees and dupattas: polyester georgette, chiffon, organza.
- Lehenga linings and can-can: polyester and nylon.
- Uniforms: poly-cotton and poly-viscose.
- Sportswear: polyester and nylon with elastane.
- Winter knits on a budget: acrylic.
Sources and uncertain points
- General textile knowledge. “Terry-cotton” and “terry-wool” are Indian trade names, not fibre names; mixes vary by mill.
- Elastane stretch and lifespan figures vary by brand and are not given here.
Check yourself
- Can you say why polyester feels sticky in humid heat?
- Do you know why synthetics are risky near flame?
- Can you measure a fabric’s stretch and recovery?
- Can you say what poly-cotton brings to a school uniform?
Key terms
- Elastane / spandex / lycra: the stretch fibre.
- Recovery: how well stretched fabric returns to size.
- Ease: extra room in a pattern beyond body size.
- Terry-cotton: trade name for poly-cotton.