The structure factor of chains dissolved in a stretched, geometrically quenched network is computed in the framework of the replica theory for networks. A variational ansatz is used. The structure factor shows features, due to the quenched disorder, leading to "lozenge"-like and the so-called "butterfly" isointensity structure factor plots. The latter patterns increase in size in the momentum transfer vector space as the degree of affinity of the network is increased, until they disappear to be replaced by the elliptical patterns.