Here's the checklist I use when a delivery of technical fabric or Polartec-branded apparel lands in my warehouse. It won't tell you whether a Denim Tears hoodie is authentic—nobody credible does that from photos—but it will catch most fakes and spec mismatches.
I'm the quality/compliance manager at a technical fabrics company. I review roughly 200 unique fabric items a year. In Q1 2024, I rejected 14% of first deliveries—mostly because the fabric didn't match the approved swatch. This is the process I follow.
People think a high price means the fabric is real. In my experience, the causation runs the other way: real material costs more because it's made to a spec. Price is a clue, not a certificate.
Use this checklist when you're ordering Polartec Power Shield fabric by the yard, approving a production run of Polartec facemask half zip hooded sweatshirts, or comparing silk jacquard fabric against a viscose nylon fabric substitute. It works for all of them, because the goal is the same: verify the material, not the marketing.
The 6-Step Verification Checklist
1. Verify the paper trail before you touch the fabric
Ask for the mill name, style number, lot number, and invoice. Genuine Polartec fabric has a style number that maps to a product family—Power Shield, Thermal Pro, Power Stretch, Power Dry, Alpha, and so on. A supplier who can't trace a roll back to a lot is a supplier who can't be audited.
I said 'Polartec Power Shield fabric by the yard.' They heard 'a black wind-resistant fleece.' We were using the same words but meaning different things. We found out when the roll arrived without a style number. Now every contract says: style number must match the approved Polartec spec.
2. Check the fiber content label
US law requires most textile products to list fiber percentages. As of February 2025, the FTC Textile Fiber Products Identification Act and its rules at 16 CFR Part 303 are the ones I cite most often. If a garment or fabric roll lacks a fiber content label, that's a red flag before any testing.
For a Polartec facemask half zip hooded sweatshirt, the fiber content on the label should match the Polartec style in your contract. Most Polartec fleece products are polyester or polyester blends. If the label says 'cotton/poly fleece' where you specified Polartec, stop the lot.
This is also where silk jacquard fabric gets confusing. Jacquard is a weave, not a fiber. Real silk jacquard should say '100% silk' or 'silk blend.' If the label says 'viscose nylon fabric' and the design is a jacquard pattern, it's not silk jacquard. It might be a fine product for some uses, but it will sew, drape, and care differently.
3. Burn a swatch before you commit to yardage
I cut a small piece from the selvedge or an inside seam and burn it in a ventilated area, away from anything flammable. The burn test doesn't identify a brand, but it identifies fiber family.
- Silk: burns slowly, self-extinguishes, smells like burnt hair, leaves ash.
- Viscose: burns quickly, smells like burning paper, leaves light ash.
- Nylon/polyester: melts and curls, leaves a hard bead.
I still kick myself for accepting a silk jacquard fabric swatch without burning it at the trade show. If I'd tested it then, I'd have caught the viscose nylon fabric blend before ordering 200 yards. The sheen was good. The burn test told the truth.
For Polartec fleece, the burn test is less useful because most of it is polyester and will melt. Use it as a supporting check. The label and paper trail matter more.
4. Look at the construction, not just the hand feel
Rub the face and the back of the fabric. Then use a loupe or a smartphone macro lens. Generic fleece often has a uniform knit. Technical knits like Power Shield have an engineered face and a brushed back. If the face is papery and the back is patchy, the roll isn't the approved standard.
So glad I checked the facemask seam on that half-zip run. I was one signature away from approving 800 Polartec facemask half zip hooded sweatshirts where the chin seam sat 3 cm off center. The fabric was good. The assembly was wrong. For any garment with a facemask, the facemask seam alignment is a separate checkpoint.
The step most people skip is measuring the facemask opening. A half zip hooded sweatshirt can have perfect fabric and still fail if the facemask pulls the hood out of shape. Add that to your spec sheet.
5. Measure weight and dimensions
Touch lies. Numbers don't. Use a calibrated scale and a sample cutter to check GSM (grams per square meter) or ounces per square yard. If the approved swatch is 230 GSM and the delivery roll is 185 GSM, that's not a tolerance issue. That's a different product.
For yardage, measure effective width and yield. A silk jacquard fabric sold by the yard at 140 cm width will not cut the same as one at 115 cm. A viscose nylon fabric can also vary in stretch and recovery. Write those numbers down.
6. Test the performance claim if the product depends on it
Polartec Power Shield is a wind-resistant stretch fleece. If you're specifying it, you're usually paying for wind resistance. Ask the supplier for a test report or a Polartec license number. If they can't provide either, assume 'similar to Power Shield' means 'not Power Shield.'
Same logic applies to other technical claims. 'Water repellent' should have a test method. 'Breathable' should have a number. If the supplier can't say which standard they tested to, the claim is just marketing.
Common Mistakes I See (and What I Do Instead)
- Relying on the hangtag. Hangtags are easy to print. This is the 'real vs fake denim tears hoodie' problem I get asked about. I don't authenticate streetwear brands—that's a different specialist—but the same fiber and seam checks catch most fakes. Real cotton fleece burns like cotton. A poly-cotton fake melts and smells like plastic.
- Skipping the scale. If you don't weigh the fabric, you're guessing. I've seen 8,000 units rejected because the GSM was 20% low. The buyer felt the fabric, but didn't measure it.
- Not keeping an approved sample. The sample is your spec. Store it sealed and labeled. Compare every delivery to it.
One more thing: a supplier who says 'this isn't our strength, here's who does it better' earns my trust for everything else. I'd rather work with a specialist who knows their limits than a generalist who overpromises. That's true whether you're buying Polartec Power Shield fabric by the yard or a silk jacquard for a capsule collection.
If you take one thing from this checklist: verify the paper trail, test the fiber, measure the weight. Then decide. The fabric will tell you the truth.