  We consider the lifetime of rectangular vertical soap films and we explore
the influence of relative humidity and both dimensions on the stability of
large soap films, reaching heights of up to 1.2 m. Using an automated rupture
detection system, we achieve a robust statistical measurement of their
lifetimes and we also measure the film thinning dynamics. We demonstrate that
drainage has a negligible impact on the film stability as opposed to
evaporation. To do so, we compare the measured lifetimes with predictions from
the Boulogne \& Dollet model \cite{BoulogneDollet2018}, originally designed to
describe the convective evaporation of hydrogels. Interestingly, we show that
this model can predict a maximum film lifetime for all sizes.
