1. A security thread, suitable for at least partial incorporation in and for use on a security document or label which consists essentially of: a plastic thread having a width and having a layer located thereon wherein said layer comprises at least two security detection features, wherein a first security detection feature is a machine-readable feature which comprises a repeating pattern, wherein said pattern comprises at least one metal region and at least one electrically isolating region, in alternating sequence, wherein said metal region(s) and said electrically isolating region(s) extend across the entire width of said plastic thread, and wherein a second security detection feature comprises metal-formed indicia.