Carbon black morphology significantly affects the transient and end-use properties of carbon black loaded polymer systems. A carbon black'particle size distribution is its single most important property, and it relates to degree of blackness and rubber reinforcement. For a given loading of carbon black, blackness and reinforcement increase with smaller particle size. Aggregate size and shape (structure) also affect a carbon black'end-use performance, as higher carbon black structure increases viscosity and improves dispersion. The stiffness (modulus) of elastomer systems becomes significantly higher with increasing structure. The preferred method for measuring these properties is transmission electron microscopy.

Carbon black aggregate dimensional and shape properties are dependent upon the nature of the system in which the sample is dispersed, as well as the mixing procedure.