Some years ago I bought a dustbin bag stuffed full of GB material and amongst it were hundreds of this issue. At the time I noticed there were some differences in the printings but put them to one side and left them for many years. Recently I spotted some booklets for sale on an auction site and I figured here is my chance to nail down those different printings. I’m focusing on the 20p Brownish Black (and Cream). Stanley Gibbons Concise GB lists three printings; Harrison & Sons using photogravure, Walsall using lithography and The House of Questa also using…