Product review (2 stars): The Lady or the Tiger?
I don't know which is worse: the rainbow of colors darkening to black on smaller, ever-hardening wick-filters w/a metal mesh or sodden & disintegrating ever-hardening wick-filters w/no metal mesh.

I willingly paid more for Vornado brand after being thoroughly disgusted with other brands and generic wick-filters. I was happy to see they're wider and denser than I've seen in the many years I've been using my Vornado 4.2 gal evaporative humidifier, and I go to the bother of switching them side to side and flipping them for maximum contact with the fluid in the bottom of the humidifier's tray.

Switching to a wick-filter w/o metal mesh insert eliminated the blackening but the trade-off is a sodden and disintegrating mess that sheds as it falls apart. Prior to these industry-wide changes I was able to prolong the life of my wick-filters  several times during the heating season by removing & soaking them in a weak vinegar & water solution to dissolve the mineral deposits. These don't even hold up just sitting in the bacteriostatic and the water treatment solutions. And I've had to clean & disinfect my humidifier more this year than ever, so I would not recommend these.