Random close pack crystal lattices have maximum densities equal to this upper limit. Random close packing does not have a precise geometric definition. It is defined statistically, and results are empirical. A container is randomly filled with objects, and then the container is shaken or tapped until the objects do not compact any further, at this point the packing state is RCP. The definition of packing fraction can be given as: "the volume taken by number of particles in a given space of volume". In other words, packing fraction defines the packing density. It has been shown that the filling fraction increases with
Packing (phallus) visibly "empty". The phrase "soft packing" refers to packing with a device that cannot be used for sexual penetration. Homemade packers may be very low-tech and consist of rolled-up socks or condoms filled with liquids or gel. There are many commercially available packers, which more realistically emulate the size, shape, color and texture of the male genitals. All soft packers are made of soft, flexible material and simulate a flaccid penis. The term "packer" most frequently describes the soft models not used for sexual activity. A few packers can be used as stand-to-pee devices (STP). These incorporate a receptacle that