Historically, anti-counterfeiting measures concerned like high-quality detail with raised intaglio printing on bills which enables non-authorities to easily spot forgeries. On coins, milled or reeded (marked with parallel grooves) edges are used to display that none of the dear metallic has been scraped off. Sense the texture of the paper. https://socialdosa.com/story9242048/the-copyright-5-gbp-bills-diaries