Sorting waste is mandatory where I live and because of the unusual collection system, the only biowaste bags we're allowed to use are the flimsy starch ones that let all moisture seep right through, making the bag wet and gross and prone to bursting open on the way to the collection point. Since used coffee filters are to blame for a lot of the excess moisture, I designed a simple contraption to dry them in before they go in the bin.

I printed mine in PLA and it has held up just fine, even though I tend to put the filter in it straight from the coffee maker while it's still hot. Should be printable in any filament tho. Print upright with the saucer part down. Supports are needed for the bottom of the funnel.