Composite right- and left-handed (CRLH) transmission lines with regularly spaced Schottky varactors are characterized for propagation of short envelope pulses. Due to strong dispersion, a short pulse cannot travel on a conventional CRLH line without distortion. This distortion is compensated for by the effects of Schottky varactors such that the line supports solitonic pulses, whose pulse width depends on the carrier frequency. It then becomes possible to find carrier frequencies at which the pulse width becomes minimal. This article describes the design criteria for propagating short envelope pulses in the lines.