The decision is per style, not per brand
Buyers often ask which fiber is better, as if a line has to commit to one. In practice most yoga collections end up with both. A core studio legging in solid black may sit on nylon and spandex, while a printed capsule or a gym-crossover short sits on polyester and spandex. The useful question is which fiber suits each role in the line.
This note walks through the differences that matter to a buyer: how each fiber feels, how it takes color and print, how it behaves in sweat and washing, and what drives its cost. It closes with a simple way to split a range between the two.
Hand feel and drape
Nylon has a smooth, cool hand and a soft drape. In an interlock knit with 20-25% spandex it produces the familiar sculpted, slightly silky legging. Polyester in a similar construction tends to feel a little crisper and more sporty. Neither is a defect; they simply read differently when a customer touches the fabric on a hanger.
The gap narrows with finishing. A brushed polyester can feel soft, and a smooth nylon can feel technical. That is why you should compare fabrics as finished swatches, not as fiber names on a list. Ask the mill for swatches of the actual finished quality you would order, with the composition and finished GSM written on the tag.
Color, dyeing and printing
This is often the deciding factor. Nylon and polyester take different dye systems, which has three practical consequences for a buyer.
- Prints: polyester is the usual base for sublimation printing, which gives sharp, all-over prints with a soft hand. Nylon is usually solid dyed, and printed nylon styles take a different route that should be discussed with the mill early.
- Matching across pieces: if a set mixes a nylon legging with a polyester top, the two pieces are dyed in different processes and may not match perfectly under every light. Keep a set on one fiber where color matching is critical.
- Color depth: both fibers can reach deep, rich shades, but each color is approved as a lab dip on the specific fabric. A shade approved on one fiber is not automatically approved on the other.
For any printed or deep color, ask for colorfastness results on the dyed or printed fabric: laundering to AATCC 61, perspiration to AATCC 15 or ISO 105-E04 and crocking to AATCC 8. A grade of 3-4 for perspiration is a common acceptance level.
Side-by-side comparison
| Factor | Nylon / spandex | Polyester / spandex |
|---|---|---|
| Typical composition | 75-80% nylon, 20-25% spandex in interlock | Polyester majority plus spandex |
| Typical leggings weight | 230-280 GSM | 230-280 GSM for gym and fitness leggings |
| Hand | Smooth, cool, soft drape | Crisper, sporty; softer when brushed |
| Decoration | Mostly solid dyed | Good base for sublimation prints |
| Odor | Generally holds odor less readily | Can hold odor more readily |
| Cost position | Higher | Lower |
| Natural fit in a line | Studio core, premium solids, bras | Prints, value lines, gym crossover |
The weights above are reference ranges. The exact weight, composition and tolerance for your program are confirmed on the fabric sheet before sampling.
Sweat, odor and washing
Both fibers are synthetic and do not absorb much water into the fiber itself, which is why both are used for moisture-wicking fabrics. The wicking behavior depends heavily on knit structure and finish, not only on the fiber. If you plan to put a wicking claim on the hang tag, read our note on moisture-wicking claims before the fabric is booked.
Polyester has a reputation for holding body odor more readily than nylon. For hot yoga and heavy training, some buyers add an anti-odor finish, but any finish should be written on the fabric sheet together with how it was verified and how long it lasts through washing. For heated classes, our hot yoga wear guide covers the other fabric decisions.
Both fibers should be checked for dimensional change after laundering, for example to AATCC 135, and for pilling to ASTM D4970 or ISO 12945-2. Pilling depends on yarn, knit and finish more than on the fiber name, so test the exact fabric you will order.
What actually drives the cost difference
SutraKnit does not publish prices; every program is quoted in writing. What we can explain is why polyester programs usually cost less. The fiber itself is less expensive, polyester fabrics are widely stocked in many colors, and sublimation printing can add pattern without a separate dyeing step for each color. Nylon programs tend to carry a higher fabric cost and, for custom colors, a dyeing step that adds time.
Fiber is only one cost driver. Construction, trims, pockets, logo method and order quantity often move the total as much as the fabric does. Our pricing guide explains the full list of drivers.
A practical way to split a line
Most first collections can be planned with a simple rule of thumb, then adjusted after sampling.
- Core solids on nylon. The legging, bra and short that customers will reorder every season, in black, navy and a few mid tones.
- Prints on polyester. Seasonal prints and limited drops, where sublimation gives freedom without a large color minimum.
- Sets on one fiber. When a top and bottom are sold as a matching set, keep both on the same fabric so the color matches.
- Value or crossover pieces on polyester. Gym shorts and training tops where the retail price is lower and the customer expects a sporty hand.
This split keeps fabric bookings simple. Each fabric quality usually has its own minimum per color at the mill, so fewer qualities across the line can make color minimums easier to meet. Reference MOQs and lead times are on the MOQ and lead time page, always confirmed in writing for each program.
Labeling and compliance notes
Whichever fiber you choose, the US label must show fiber content by percentage, country of origin and dealer identity under the Textile Fiber Products Identification Act (16 CFR 303), plus care instructions under the Care Labeling Rule (16 CFR 423). Under the clothing flammability rule (16 CFR 1610), fabrics made entirely of nylon or polyester are among those exempt from testing, but a blend with spandex is not covered by that wording, so check the status of your exact composition with your compliance adviser.
If you are considering recycled versions of either fiber, the claim and documentation rules are different. See recycled nylon and polyester.
What to send the desk
Send a list of the styles in your line, the colorways for each and whether any are printed. Add one or two reference garments if you have them. The desk will propose a fiber for each style, request finished swatches from the partner mills and set up the fabric sheet so that sampling starts from agreed numbers. You can start from the fabric library or go straight to a quote request.