Clogging is a critical but common problem experienced during electrospinning, especially when a high-volatility solvent is used to prepare a polymer solution. An ability to mathematically predict the time at which clogging starts to occur is thus of great importance. However, existing mathematical models could not predict the clogging time well since solvent evaporation is almost always neglected in those models. In this study, onset of clogging of a model biopolymer, i.e., zein in ethanol, was predicted through the use of a model developed based on scaling analysis; the effect of solvent evaporation is also included in the model. Experiments were also conducted to verify the predictability of the developed model. It was found that the predicted clogging time agreed well with the experimental results. (C) 2010 Elsevier Ltd. All rights reserved.