  We report an experimental study of quench condensed ($2K\le T \le 15K$)
disordered ultrathin films of {\rm Bi} where localisation effects and
superconductivity compete. Experiments are done with different substrates
and/or different underlayers. Quasi-free standing films of {\rm Bi}, prepared
by quenching {\rm Bi} vapours onto solid {\rm Xe}, are also studied. The
results show a dependence of the transport properties both on the dielectric
constant of the substrate/underlayer as well as the temperature of quench
condensation. RHEED studies indicate that quantum size effects are important in
these systems. In this paper, we try to correlate the structure of the films to
the transport properties obtained.
