Starting from alkoxides prepared in the laboratory, undoped and Sb-doped tin dioxide (SnO2) thin films have been deposited using the sol-gel dip-coating method. These layers have been characterized in relation to the environmental conditions during the pulling phase of the process. Among other parameters, the relative humidity ratio in the dip-coating apparatus has been found to be a key factor, for the morphology of the films as well as for the introduction of Sb-doping atoms. Characterization has been carried out by scanning electron microscopy, high resolution transmission electron microscopy and electron spectroscopy for chemical analysis.