Solvent-free epoxy resin coatings have been applied to thin steel shims and cured under dry conditions. The internal stresses that formed in coatings cured on substrates that were free-to-bend during curing were significantly higher than those in coatings cured on substrates that were held flat during curing. Models have been developed to account for the behaviour. It is shown that the behaviour can be explained with reference to a layer-by-layer curing process in which layers that solidify progressively later in the process do so onto a substrate that is already bent and that this, therefore, becomes their reference (unstressed) state. It is shown that stress relaxation during the post-curing period does not cause any additional difference as long as the coating behaves as a linear viscoelastic material. Strategies for determining the internal stress in a coating by measuring the bending moment required to flatten the coating-substrate assembly are discussed.