A diagrammatic representation of data on scattering from large particles, corresponding to the equation: $$\frac{K_c}{\mathrm{\Delta }R(\theta )}=\frac{1}{{\overline{M}}_{\text{w}}P(\theta )}+2A_{2}c+\text{ ... }$$ and used for the simultaneous evaluation of the mass average molar mass, ${\overline{M}}_{\text{w}}$, the second virial coefficient of the chemical potential, $A_2$, and (usually) the z-average radius of gyration, $<s^2{>}_{\text{z}}^{\frac{1}{2}}$; $c$ is the mass concentration of the solute, $\mathrm{\Delta }R(\theta )$ the excess Rayleigh ratio, and $P(\theta )$ the particle scattering function that comprises (usually) the z-average radius of gyration. $K$ depends on the solute, the temperature and the type of radiation employed. Several modifications of the Zimm plot are in frequent use; the most common one uses the excess scattering instead of the excess Rayleigh ratio.