Abstract Solution small-angle scattering as an analytical method has a long history and it is widely applied today. X-rays or neutrons can be used, thus exploiting their complementary characteristics as scattering probes. A solution small-angle scattering database is available and is well organized by the community. In the pursuit of accuracy, a very interesting state of matter closer to that of the living cell is the liquid state. The biological small-angle scattering community has established stringent attention to data and model validations so as to reduce the potential for over-interpretation or even being misled. A key advantage of the liquid state is that flexibility of the macromolecule is not restricted by lattice contacts. Hence structure ensembles may need to be considered.