Parametric amplifiers based on non-linear superconducting transmission lines have seen rapid progress in the last few years, although many fabricated samples still behave well below the optimal performance that is theorised. A part of this discrepancy is due to the attenuation of travelling waves that occurs in realised schemes due to dielectric losses or resistance losses on the superconductor surface. As interests turn towards designs utilising more complex non-linear elements such as SNAILs or materials near the superconductor–insulator transition, we address the question of dissipative losses in heretofore common schemes with a methodology that can be extended to other superconducting metamaterial devices.