A shear-lag approach to the prediction of the tensile strength of paper is outlined and examined. It is demonstrated that transition of fiber strength to paper strength requires long fibers for sheets with weak fiber-fiber bonds, or low relative bonded area. Fiber pull-out is encountered even for highly bonded sheets. Predictions of tensile strength for papers of the same fiber length, but with different beating degrees, and for papers with different fiber lengths and beating degrees, are in quantitative agreement with previously published data.