[en] We present a progress report on the Core Program project dealing with X-ray weak Seyfert 2 galaxies. The aim of the project is to increase the sample of Seyfert 2 galaxies with measured hard X-ray spectra, by adding progressively weaker objects within a well-defined optical sample. The hard X-ray information, together with the [OIII] and IR fluxes, the orientation of the host galaxy and the geometry of the ionization cone, should give the distribution of the absorbing column N_H, and assess the reliability of various proposed 'isotropic' indicators of the luminosity. We have up to now a 100% detection rate, and find systematically low (X[OIII]), high N_H, and high Fe EW. While the first finding is due to our attempt of removing pre-existing biases, the remaining two support strongly the unified scenario, and point to a fraction of X-ray thick sources higher than usually assumed