100 Dollars Oval Security Device

The "Oval Security Device" designation distinguishes this from the earlier polymer issues in the Solomon Islands series — a mid-series security upgrade rather than a new denomination release. Thomas De La Rue's hybrid substrate combines a paper-like feel with a polymer core, a format developed partly in response to counterfeiting pressures on Pacific island currencies where enforcement infrastructure is limited.

The oval security device itself is a windowed thread variant engineered to be difficult to replicate without access to industrial foiling equipment — a meaningful deterrent in low-volume currency markets where traditional intaglio printing alone was deemed insufficient.