This paper reports the formation of monomolecular lamellar arrays of thionine (TH) and methylene blue (MB) by self-assembly in the interlayer of metal phosphates formulated as M(IV)(HPO4)2• H2O, with M ˭Sn and Zr (α-SnP and α-ZrP). We apply the molecular exciton model to the interpretation of the electronic reflectance spectra of the intercalation compounds and find that metachromatia upon sorption and intercalation is understandable with exciton theory. We describe how delaminated α-SnP and α-ZrP are useful as template layers for self-assembly of amphiphilic dyes in well-ordered monolayers. Starting with well-characterized template layers, it is possible to quantify the self-assembly steps and infer how the order of the active sites in the template layers extends to the molecular aggregates. We find that the dye layers achieve a high orientational order and that the organization of active sites in the template layers is an essential factor. The agreement between observed and calculated exciton displacement terms proves the possibility of deducing ultra-structure characteristics of nano-composite materials by simple absorption measurements.