Often driven by the desire to avoid the necessity of cleaning the gutters two, or three, or even four times a year, various different ideas have led to the creation of gutter guards, gutter covers, and gutter screens. Gutter screens are not like the window screens you use to keep out flies and mosquitoes. Screens with smaller holes trap more small particles on top. So what about gutter filters?
The simplest solution is some kind of gutter screen. When water is poured on the screen it readily runs through the holes. This fine material will readily pass through the diamond-shaped holes. Capillary action makes the water try to stick to the surface of the gutter cover. On a rain gutter cover, the lip of the cover is positioned so the debris falls outside the rain gutter, but the water falling from the tab falls inside the gutter.