Quality scrim for me. I've recently tested 4 different microfiber cloths & ALL leave a mess on the glass when detailing. Not always apparent 'till the sun shines but when it does it looks bad! Also they don't last long before needing a fresh one. I really wanted them to work for 'cos they're more convenient (softer, easier to handle) but I just don't like them for detailing, better for glass cleaning though if you use the right side.