“Made from recycled polyester” is a simple label to read, but the process behind it involves several real steps — from collection to fiber production to the hand-designed print that ends up on your leggings. Here’s a closer look at how plastic waste actually becomes wearable art.

Step 1: Collection and Sorting

The process starts with post-consumer plastic — most commonly PET bottles, collected and sorted by material type and color. Clear PET bottles are generally preferred as a starting material, since they’re easier to process into consistent, high-quality fiber than mixed-color plastic waste.

Step 2: Cleaning and Shredding

Collected bottles are cleaned to remove labels, caps, and residue, then shredded into small plastic flakes. This step matters more than it sounds — contamination at this stage can weaken the resulting fiber, so thorough cleaning is essential to producing durable, high-quality yarn later in the process.

Step 3: Melting and Extrusion

The cleaned plastic flakes are melted down and extruded through small nozzles called spinnerets, forming continuous, thin filaments. This is the point where plastic waste physically becomes something closer to thread — a transformation that’s honestly a little remarkable to think about.

Step 4: Spinning Into Yarn

The filaments are cooled, stretched, and spun into yarn — recycled polyester yarn, in this case, ready to be knitted into fabric. This yarn is typically blended with spandex at this stage or during knitting, giving the finished fabric the four-way stretch and recovery needed for activewear.

Step 5: Knitting the Base Fabric

The recycled polyester-spandex yarn is knitted into fabric using techniques designed for performance activewear — dense enough to stay opaque under stretch (squat-proof), with enough elasticity to move fluidly with the body.

Step 6: Applying the Original Art Print

This is where Njálla’s process diverges from a typical recycled-fabric supply chain. Rather than applying a licensed, generic pattern, we start with original art — hand-painted or hand-drawn, inspired by Finnish landscapes like birch forests or the polar night. That artwork is carefully adapted into a seamless, repeatable print file, then applied to the fabric through a sublimation printing process that bonds color directly into the synthetic fibers, keeping detail and vibrancy intact through repeated washing.

Step 7: Cutting and Sewing

The printed fabric is cut according to individually graded patterns for each size (not just scaled uniformly), then sewn using flat, reinforced seams designed to withstand squats, stretches, and repeated washing without unraveling.

Step 8: Quality Checks and Final Product

Each finished piece is checked for consistency in fit, print placement, and construction before it’s ready to ship — the final step in a process that started with a discarded plastic bottle and ends with a pair of leggings built to be worn for years.

Why We’re Transparent About This

It would be easy to just print “73% recycled polyester” on a label and leave it there. But understanding the actual steps — collection, cleaning, extrusion, spinning, knitting, hand-designed printing, and construction — makes it clearer why sustainable materials and thoughtful design genuinely matter, and why a garment made this way deserves to be cared for and worn for a long time.

Curious to see the finished result? Explore our recycled-material collection and hold a piece of this process in your hands.

Explore the Njálla Collection

Shop our sustainable yoga leggings and yoga tops - recycled fabric, handmade Nordic nature art, ethically made. Not sure where to start? Read our complete buying guide.