Polyester and nylon fabric end up in the same conversation constantly, and it's easy to see why. Both are synthetic, both are durable, and both show up in everything from tote bags to backpacks to travel accessories. But if you're sewing bags to sell or use, the difference between them matters more than most sewists expect. Getting it wrong means a bag that stretches out of shape, fades after a season, or costs far more than it needed to.
What actually separates these two fabrics
Nylon was invented first, arriving in the 1930s as the original synthetic fabric. Polyester followed in the 1940s. Both are petroleum-derived, woven into sheets using continuous filament fibres, and finished in an enormous range of weights and weaves. That's roughly where the similarities end.
Nylon is stronger per gram than polyester. It has a higher tensile strength, which means a lightweight nylon ripstop resists tearing better than an equivalent-weight polyester. It also has more natural elasticity, so it bounces back after stretching rather than deforming. For bags that carry heavy loads repeatedly, that recovery matters.
Polyester, by contrast, is stiffer and holds its shape better under light loads. It doesn't absorb as much water as nylon does (nylon absorbs around 4–8% of its weight in moisture; polyester sits below 1%), and it resists UV degradation far better. A bag left in the car or a market stall in direct Australian sun will hold its colour much longer if it's polyester.
Which handles better at the sewing machine
For most bag-makers, sewing experience is what tips the decision. Nylon is slippery. The surface is smooth and the fabric slides under the presser foot in ways that frustrate even experienced sewists. Walking feet help, and clips rather than pins are strongly recommended. The pay-off is that nylon sews cleanly through thick layers without bunching, which is useful for gussets and boxed corners.
Polyester behaves more predictably on a standard machine. It grips slightly better, feeds more evenly, and doesn't skew as badly when cutting. For sewists who are new to bag-making or working without a walking foot, polyester fabrics are usually the easier starting point.
Thread choice matters for both. A polyester thread is the correct match for both fabrics. Cotton thread will break down faster than the fabric itself, which creates a structural failure point in a bag that's supposed to last years.
Weight, coating, and the GSM question
Neither polyester nor nylon is useful without knowing the weight and finish. A 75D polyester oxford and a 420D nylon oxford are entirely different beasts. The denier number (D) tells you the thickness of the individual fibres; the weave pattern (ripstop, oxford, plain) tells you the structure. Both fabrics also come coated or uncoated, and for bag-making, a polyurethane (PU) coating or water-resistant finish changes the project entirely.
Coated nylon is the go-to for bags that need to handle rain. It dries faster than coated polyester because the coating limits how much moisture the base fabric holds. Coated polyester works well for structured bags where you want the walls to hold their shape without interfacing. If you're building a bag or travel accessory that needs to perform in multiple conditions, coated nylon with a woven polyester lining covers both bases.
For a practical reference point, understanding fabric GSM is just as relevant here as it is for wovens and knits. A 200–300 GSM nylon or polyester oxford works for everyday totes and zipper bags. Anything heavier than 400 GSM is better suited to structured backpacks and market bags that carry serious weight.
Cost and availability for Australian sewists
Polyester fabrics are cheaper to produce and cheaper to buy in Australia. For small batch bag-making and market stall production, the cost difference is real and compounds quickly across large cuts. Nylon costs more, particularly in the lighter-weight technical ripstop grades.
That cost difference is justified when durability under load is the priority. A kids' backpack, a reusable shopping bag, or a weekend travel bag benefits from nylon's strength. A lined tote, a market carry bag, or a fabric project bag used lightly does not need to pay the nylon premium.
Custom printed fabric in these bases is trickier. Digital printing works best on fabrics with a high polyester content because the dye sublimation process bonds directly to polyester fibres. Nylon doesn't accept dye sublimation inks the same way, which is why most digitally printed bag fabrics you'll find are polyester-based. If you're combining a custom print with bag construction, polyester is almost always the print-ready option.
A quick comparison by project type
- Everyday tote bags: polyester oxford, 200–300 GSM, uncoated.
- Reusable shopping bags: nylon ripstop for packability, or heavy polyester for structure.
- Travel accessories and pouches: coated polyester or coated nylon depending on rain exposure.
- Kids' bags and backpacks: nylon, 420D or higher, for abrasion resistance.
- Custom printed bags: polyester base for digital print compatibility.
The short answer
Nylon performs better under stress. Polyester performs better in sunlight, holds colour longer, costs less, and accepts digital prints. For most bag projects sewn in Australia, polyester is the practical default. Nylon earns its place when the bag needs to carry heavy loads, pack down small, or survive rough handling over years of use. Knowing which one you're reaching for before you cut saves a lot of mid-project regret.