Sweden Postage Stamp with Wavy Lines Watermark

Sweden · 1900 ·

This stamp is part of a series from Sweden characterized by the 'Wavy Lines Wide Up' watermark. This watermark, a security feature embedded in the paper during manufacturing, consists of continuous, widely spaced undulating lines pointing upwards. Such watermarks were common on definitive issues to prevent forgery.

Watermarks have been a standard security feature on Swedish stamps for much of their history, with various patterns used to identify different printings and paper batches over the years.