Is it possible for POLYMAT to identify the parameters of a viscoelastic model without the Storage and Loss moduli (G’ and G”) data by using the viscosity and transient extension data curves only? It seems that POLYMAT does not want to perform the fit without G’ and G” data and issues a warning. Is there a way to get around this? This is a somewhat unusual situation, but we understand that acquiring oscillatory data is not always feasible for all materials. The following workaround is suggested: •Create dummy files for G’ and G” properties and read them into POLYMAT. •Set the weight of these curves to be very small like 1.0e-12 in Numerical options for fitting under Automatic fitting so that POLYMAT effectively does not use them in curve fitting. •Fix the relaxation time to an appropriate value. Since we are using dummy G’ and G”, it appears reasonable that the value of the relaxation time will have to be supplied to the program. •Do the curve fitting and get other parameters.