  The flexibility of two-dimensional (2D) materials enables static and dynamic
ripples that are known to cause lateral contraction, shrinking of the material
boundary. However, the limits of 2D materials' \emph{lateral expansion} are
unknown. Therefore, here we discuss the limits of intrinsic lateral expansion
of 2D materials that are modified by compressive line defects. Using thin sheet
elasticity theory and sequential multiscale modeling, we find that the lateral
expansion is inevitably limited by the onset of rippling. The maximum lateral
expansion $\chi_{max}\approx 2.1\cdot t^2\sigma_d$, governed by the elastic
thickness $t$ and the defect density $\sigma_d$, remains typically well below
one percent. In addition to providing insight to the limits of 2D materials'
mechanical limits and applications, the results highlight the potential of line
defects in strain engineering, since for graphene they suggest giant
pseudomagnetic fields that can exceed $1000$~T.
