The science — how it actually works
Microfibre is split polyester/polyamide — typically 70/30 or 80/20. Splitting the fibre multiplies its surface area and creates hooked, wedge-shaped edges that trap and hold particles inside the pile instead of pushing them along the paint. That's the entire mechanism, and it's why a cotton rag scratches and a good microfibre doesn't.
GSM = grams per square metre — the density of the pile. 400gsm is the sweet spot for buffing and coating removal: plush enough to hold what it lifts, not so plush it smears product.
Edgeless matters. A stitched polyester border is a hard edge dragged across soft clear coat. It's one of the most common causes of self-inflicted scratches — from the very cloth you bought to prevent them.