A device is presented comprising a multi-layer structure with a plurality of metal islands on the surface of a solid transparent substrate. When the polycarboxylate dispersant and the naphthalene dispersant of the admixture formulation are combined at various ratios the admixture formulation reduces the tendency for bleed and segregation in cementitious mixtures without increasing water demand, retarding setting, increasing water sensitivity, promoting high viscosity, or reducing flow retention. The additional codes may be written to a nonvolatile medium.