10 Pounds

Guernsey's P#57 series ran for nearly three decades across multiple signature and security thread variants, making it one of the longer-lived modern issues from the Channel Islands. The progression from solid to segmented security thread — and later to the narrow segmented variant under Haines — tracks the incremental upgrades De La Rue applied across its client base during the late 1990s and 2000s. The Clark segmented thread variant is split at serial D900001, an unusually precise documented breakpoint that collectors can verify from the number prefix alone.