The new partnership between the NBA and Nike is off to a rough start. The new NBA jerseys have been ripping left and right, and neither Nike nor the NBA can seem to pinpoint a reason why.

This isn’t a new phenomenon, but we’ve never seen jerseys being slashed this frequently. In just under a month of regular-season basketball, six players have seen their jerseys torn one way or another, including prominent names like LeBron James, Draymond Green, Kevin Love, and Ben Simmons.

What’s the problem? In a statement to SB Nation, a Nike spokesman cited the need to standardize the “embellishment process and enhancing the seam strength of the game day jerseys” as they move forward into the season.

Nike didn’t elaborate on what exactly that meant, so to understand the problem further, we asked product testers and experts from the fashion industry to find out.

What does “embellishment” mean and what does that have to do with jerseys ripping?

Slade: It’s the process where they put the numbers on. Maybe that process is causing some weak spots in the knit and they’re trying something different. Because even if you feel the jerseys, they don’t feel super thin.

So maybe that process is breaking the tension that is allowing some of to give way. It could be reducing the tensile strength.

Have you ever seen or experienced this with a similar product before?

Tse: Not necessarily in athletic wear, but they’ve used recycled materials on sneakers before.

The last item that had an issue for me was something people have actually been playing with — the Nike Zoom KD 10. I had an issue with it, that I’m sure they’ve fixed by now. But the lace loops pretty much ripped on me while I was playing.

Wait, what happened?

Tse: On the lace loop it’s covered by three threads, but if someone steps on your shoe a particular way and comes down on your foot, they can pull the fabric on the material off your shoe and drag it and with the amount of friction that’s pulled off your feet, the material can rip.

That’s also the case if you tug on a jersey.

Nike used recycled bottles to create threads for these jerseys. Does that matter?

Quevedo: I’m not a fabric engineer or chemist, I'm a fashion designer.

But melting plastic and turning them into fabric has been around since the 1980s when they started to use that process with fleece fabric. Also, the weight has nothing to do with the strength of fabric.

Nike intentionally made this product lighter than previous jerseys used. Does that explain the tearing?

Quevedo: The weight has nothing to do with the strength of fabric. Fabric strength, or "tensile strength," is the maximum stress it can withstand before breaking its ultimate tensile strength.

There are many factors that affect tensile strength: The kind of fiber used, the way it was knitted or woven, and how closely the yarns are placed in the weaving or knitting process. Weight has nothing to do with strength.

Does Nike have this same difficulty with other products they’ve used recycled bottles with?

Slade: No. This isn’t the first time they’ve used recycled bottles. That’s why it’s so weird that this his happening.

They’ve been doing jerseys with recycled material for a while. They’ve been doing soccer jerseys with recycled material. They’ve been doing football jerseys with recycled plastic. I don’t know if these are thinner and that’s what’s causing it, but they’ve been using recycled plastic for at least a few years now.

Related Why NBA Jerseys Are Slightly Different Every Year

Why don’t we see this anywhere else? Nike makes college jerseys and has made Team USA jerseys in the past.

Tse: We don’t see this mostly because it depends on the platform. College basketball is a big thing, but it’s not as global as the NBA. You won’t see it as intuitively or as often. And you have to realize that it’s not just Nike making jerseys at the college level. It’s also Adidas and it’s also Under Armour. So it’s harder to put under a microscope. So the scope is really wide.

Are there any other factors that we could be overlooking that’s causing this trend?

Quevedo: Not knowing all the variables that affect fabric performance, you have to look at everything from fiber, chemical makeup of that fiber, how it was knitted, what pattern was used to knit the fabric, how moisture or dryness can affect performance, how it was sewn together, and were there other things such as printing or embroidery was used.

Another question to ask is where on the jersey is it tearing or wearing away of the jersey? Is there a common area where the tearing is happening?

How does Nike fix this?

Tse: In certain cases, Nike uses AeroSwift technology. It’s a fusion of material — it’s like using heat to mold the material together. It could be the way that the jersey is held together. There are numerous possibilities. Maybe they use a new stitching format or a fusing format to alleviate the issue.

But you can never count out Nike because their [research and development] is top notch.