I have tested many filament clips during years but every one has some flaws – from annoying everyday use to unreliable attachment. There is no reason to be frustrated by the loose or entangled material anymore. These two clips for the most common 1.75 and 2.85mm filaments were designed from scratch to suit spools of Fillamentum brand (old black and new transparent). You can 3D print them very fast and with minimum of material. The same clips could work also with some other spool types, I have tested standard 0.75 to 1kg spools from Innofil3D, Prusa, Ultimaker etc. Just test yours.