identified by comparison with a genuine stamp. Crucially, on the genuine stamps the lines appear underneath the gum. Notes and references Further reading Great Britain Concise Stamp Catalogue 2008, Stanley Gibbons, London, 2008. . "A View of Wildings" by Rob Tibbenham in The GBPS Newsletter, No.268, March/April 2001. External links Pictures of typical graphite lined stamps. Postage stamps of the United Kingdom Postal system of the United Kingdom Philatelic terminology