Microfiber is made primarily from two synthetic polymers: polyester and polyamide (nylon). These two materials are blended together, with polyester typically making up 70% to 80% of the fabric and polyamide comprising the remaining 20% to 30%. The fibers are then manufactured to an extremely fine thickness, at least 200 times thinner than a human hair, which is what gives microfiber its distinctive softness and cleaning ability.
What Counts as Microfiber
Not every thin synthetic fabric qualifies as microfiber. To earn the name, a fiber must have a linear density below 1 decitex, a measurement that describes how much one meter of the fiber weighs. Anything above that threshold is just a regular synthetic fiber. This ultra-fine diameter is what creates microfiber’s enormous surface area relative to its weight, and that surface area is responsible for most of its useful properties: it picks up more dust, absorbs more liquid, and feels softer against skin than conventional fabrics.
The Polyester-Polyamide Blend
The two components in microfiber serve different roles. Polyester provides structure and durability. It’s the backbone of the fabric, resistant to stretching and shrinking. Polyamide adds softness and absorbency, giving the cloth its ability to soak up water and trap fine particles.
The ratio between the two matters, especially for cleaning applications. A 70/30 or 80/20 polyester-to-polyamide blend is considered ideal for most purposes. Ratios like 85/15 or 90/10 contain so little polyamide that the fabric loses much of its absorbency and can even scratch delicate surfaces like automotive paint or eyeglass lenses. If you’re buying microfiber cloths for cleaning, the blend ratio is one of the first things worth checking.
How Microfiber Is Manufactured
Microfiber production starts with melt-spinning, the most common industrial method for creating synthetic fibers. Polyester and polyamide are melted separately, then extruded together through tiny openings called spinnerets. The two polymers are combined into a single strand in a configuration sometimes described as “pie-wedge” or “islands-in-the-sea,” where alternating segments of each polymer sit side by side within one filament. Cool air solidifies the strand as it emerges, and mechanical drawing stretches it to improve strength.
The real magic happens in a second step called splitting. The combined filament is mechanically or chemically processed so the two polymers separate from each other, creating dozens of ultra-fine sub-fibers from what was originally one strand. This splitting is what produces the characteristic star-shaped cross-section visible under a microscope, with tiny wedges and channels that trap dirt and moisture. Without splitting, the fiber would be smooth and relatively useless for cleaning.
Split vs. Non-Split Microfiber
Not all microfiber products go through the splitting process. Non-split microfiber is used in clothing, upholstery, and decorative fabrics where the goal is a soft feel rather than cleaning power. Split microfiber, the type sold as cleaning cloths and mops, has its fibers opened up to maximize surface area and absorbency.
You can test whether a microfiber cloth is split with a simple check. Drag it lightly across your hand: split microfiber will catch slightly on your skin. You can also push it into a small water spill. If it absorbs the water immediately, it’s split. If it pushes the water across the surface, the fibers haven’t been properly opened and the cloth won’t clean well.
Less Common Microfiber Materials
While polyester and polyamide dominate, not all microfiber is purely synthetic. Cellulose-based fibers like lyocell can also be produced at microfiber-scale diameters. Lyocell starts as wood pulp, which is dissolved into a slurry and then wet-spun into filaments. The result is a fiber with properties closer to cotton than polyester, but manufactured to be much finer. These plant-derived microfibers show up in some clothing and bedding marketed as more environmentally friendly alternatives, though they’re far less common than the standard polyester-polyamide blend.
The Microplastic Problem
Because most microfiber is synthetic plastic, it sheds tiny fragments every time it’s washed. A single laundry cycle can release anywhere from roughly 9,000 to nearly 7 million individual microfibers into wastewater, depending on the fabric. That range is enormous because shedding depends heavily on fabric type, construction, and thickness.
Fleece and jersey-knit polyester are the worst offenders, releasing about six times more microfibers per wash than woven nylon fabrics. A 50/50 cotton-polyester fleece blend can shed over 800 milligrams of fiber per kilogram of fabric in a single wash, placing it among the highest-shedding textiles tested. These fibers are small enough to pass through many wastewater treatment filters and eventually reach rivers and oceans.
It’s worth noting that natural fibers shed too. Cotton and wool textiles release comparable amounts of lint by weight during washing. The difference is that cotton and wool fibers biodegrade over time, while polyester and nylon fragments persist in the environment for decades. Using a microfiber-catching laundry bag or filter can reduce the number of fibers that make it into wastewater, though no consumer solution eliminates shedding entirely.
What the Fabric Weight Tells You
Beyond the blend ratio, microfiber quality is often described by GSM, or grams per square meter. This number tells you how dense and plush the fabric is. A microfiber cloth at 200 GSM is thin and lightweight, suitable for wiping screens or glasses. At 300 GSM or higher, the cloth is thicker, more absorbent, and better suited for heavy-duty cleaning tasks like scrubbing countertops or drying a car. For general household cleaning, 300 GSM with an 80/20 or 75/25 polyester-to-polyamide ratio is a reliable baseline to look for.