A layered preparation method is introduced that produces structured MALDI targets with well-defined phase sizes and compositions. Tri-a-naphthyl benzene is a glassy matrix that forms smooth films. It is layered with polystyrenes or polyethylene glycol dissolved in selective solvents that do not affect previously applied layers. Both hydrogenous and deuterated polystyrenes are used in the layering process so that they can be distinguished by MALDI. The results are consistent with the solvent-free sample preparation method and small angle neutron scattering studies, which show that molecular dispersion of individual polymer molecules is not necessary for strong signals. Individual polymer molecules in micron sized layers produce varied MALDI signals depending on their location within the aggregates. This suggests a possible mechanism for biasing in MALDI due to unequal distributions of polymers throughout the sample.