The next generation of Cosmic Ray Background detectors require large area filters in the microwave part of the spectrum between 100 to 300 Gigahertz. These filters are essential to the extremely sensitive detection of the cosmic background radiation at the level of one part in a billion and will require precise fabrication of metallic structures on a polymer substrate. These filters will be placed in DOE supported next generation detectors in extremely dry areas like Chile or Antarctica. The stringent requirements for the manufacturing of these filters require new and novel techniques. The objective is to use new and emerging additive manufacturing technologies by Obsidian to address this problem. Based on design and simulations at Brookhaven National Laboratory, Obsidian will 3D print the filter on polymer substrates which will then be characterized and tested at Brookhaven. After the structures have been optimized we will then use the data as a springboard for scaling up and making up entire filter stacks for Phase2 which can then be commercialized. One major commercial application are the use of additively manufactured filters for applications in Terahertz cameras ? which are useful for detection of skin cancer, explosive devices and also contraband. With experience in Additive manufacturing of the filters they can also be used in commercial spectrometers.