For nanoparticles larger than the thickness of the lipid bilayers, studies of wrapping by membranes are therefore an important step toward achieving a systematic understanding of nanotoxicology. This chapter introduces a continuum membrane model and focus on the roles of specific nanodescriptors for wrapping, such as particle size, shape, softness, and surface functionalization. It reviews the effects of cooperative interactions between particles, multicomponent biological membranes, membrane curvature prior to wrapping, and spontaneous membrane curvature on wrapping. Models for nanoparticle–membrane interactions can be chemically specific for a particular system or generic for systematic studies of specific descriptors, such as nanoparticle shape and size. Enrichment of favorable components has also been reported for membranes with charged proteins and lipids, as well as for membranes with conical proteins that locally decrease the bending energy for wrapping. Finite membrane curvature prior to wrapping and spontaneous membrane curvature can facilitate or hinder nanoparticle binding and envelopment.