Graphical Abstract Highlights d Linear growth of the epidermis during postnatal development d Constant imbalance of self-renewal and decreasing proliferation leads to IFE growth d Higher molecular homogeneity in developmental progenitors d Orientation of clonal growth follows orientation of collagen fibers In Brief During postnatal growth, tissues steadily grow until they achieve their final size. Looking at the interfollicular epidermis in mice, Dekoninck et al. find that progenitors present an excess of self-renewing division throughout the development. This imbalance, coupled with an ever-decreasing proliferation rate in both scale and interscale compartments, provides linear tissue expansion and maintenance of skin barrier function at the same time.