  For a profinite group $G$ and a rigid analytic space $X$, we study when an
$\mathcal O_X(X)$-linear representation $V$ of $G$ admits a lattice, i.e. an
$\mathcal O_{\mathcal X}(\mathcal X)$-linear model for a formal model $\mathcal
X$ of $X$ in the sense of Berthelot. We give a positive answer, under mild
assumptions, when $X$ is a "wide open" space. Via such a result, we are able to
describe explicit subdomains of $X$ over which $V$ is constant after reduction
modulo a power of $p$. As an application, we prove some explicit results on the
reduction of sheaves of crystalline and semistable representations modulo
powers of $p$. We also give an application to the pseudorepresentation carried
by the Coleman--Mazur eigencurve.
