A wet paint film of uniform thickness, \(\delta\), is painted on a vertical wall. The wet paint can be approximated as a Bingham fluid with a yield stress, \(\tau_{y}\), and density, \(ho\). Derive an expression for the maximum value of \(\delta\) that can be sustained without having the paint flow down the wall. Calculate the maximum thickness for lithographic ink whose yield stress \(\tau_{y}=40 \mathrm{~Pa}\) and density is approximately \(1000 \mathrm{~kg} / \mathrm{m}^{3}\).