Scientific program bringing together the stakeholders interested in the determination of the neutron skin of a heavy nucleus (e.g., Pb) and its implications on the density dependence of the symmetry energy. Although various meetings of this sort have already been organized, it is the primary goal of the program to establish quantitatively the strengths and limitations of the various experimental techniques. This requires a detailed analysis of the systematic errors. Moreover, in the case that theory must be used to connect the experimental observable to the neutron skin, it also essential to quantify both the statistical and systematic errors associated with such a theory. Finally, we aim to establish what is the required precision on the neutron skin that will allow a meaningful constraint on the density dependence of the symmetry energy and ultimately on astrophysical observables. The introductory workshop serves to pre-define goals and expectation and a two-weeks scientific program in spring next year.