Black Widow (also known as a Black Widow Ultra in Europe) is a non-commercial open source project to design a paint mix for the base of a DIY projection screen. Anonymous DIYers responsible for popularizing Black Widow in the DIY community include Mechman Alternators (US), Wbassett (US) and Custard10 (EU). The paint mix is made from easily accessible materials and could outperform much more expensive commercial projection screens. Black Widow has four special slick agents that seek to be competitive with other projection screen manufactures. A typical formula for Black Widow is 4 parts commercial water-based matte white paint, tinted with black paint to a shade of N7.8 (although N8 is acceptable, and simpler to make), and 1 part water-based fine silver paint.