A novel, fledgling approach to the filtering of EUV radiation for laboratory and space applications is reviewed. Foils perforated by a set of parallel channels with submicron diameters serve as wavelength-dependent filters. Each channel passes photons when the wavelength is much smaller than the channel diameter. The transmission of the channel drops dramatically, however, when the wavelength becomes comparable to or larger than the channel diameter. The relevant theoretical considerations as well as available experimental data are presented. Several different ways to manufacture such kind of filters are outlined, including nuclear track filters, anodized metal films, and microchannel plate technology. Advantages and disadvantages of each technique are discussed. The history of the work in the field as well as prospects for the future are presented.© (1991) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.