The thermal-relic mechanism for the production of dark-matter in the early universe. combined with the precision measurements of the cosmic microwave background and the lack of observation of dark matter at the LHC. motivates the search for dark matter in the mass range between 1 MeV and 1 GeV. We describe the concept for the Light Dark Matter Experiment (LDMX). https://cosmeticssquadets.shop/product-category/powder-foundation/