A method of preparing a mailpiece includes applying a mailpiece identification code that uniquely identifies the mailpiece, and applying a destination code to the mailpiece signifying at least part of an address. Said heterogeneous catalysts are generated by immobilizing preformed monometallic or multimetallic metal oxide particles in situ on an oxidic or non-oxidic carrier, wherefore metal oxide colloids which are stabilized by hydroxide ions and immobilized on carriers contained in the suspension are generated from conventional, water-soluble metal salts by means of hydrolysis and condensation. The hollow nano-tube structure facilitates salt dissociation, serves temporarily storage for lithium ions, creates new conducting mechanism and improves the conductivity thereof. The barrier remains permanently connected to the first and second regions of the foam member. A model using the CFA and the GF set is optimized by simultaneously fitting a plurality of the spectra while minimizing error compared to the target thicknesses.