Additives are extra substances blended into a base material to change how it prints or performs. In 3D printer filament, they can improve flow, reduce brittleness, change color, or alter heat resistance and surface behavior. That means a spool labeled with one plastic name may actually be a carefully tuned material system, not a pure resin.
For cyber security, additives matter because material composition affects trust in the supply chain and the reliability of manufactured parts. A changed formulation can make a part harder to inspect, easier to counterfeit, or more likely to fail in service. Defenders look for specifications, provenance, and testing to confirm that the delivered material matches what was ordered. In practice, additives are one of the reasons two apparently identical filaments can behave very differently in a printer and in the finished object.