Diamine Registrar's Ink The Geniune Article! Permanent and waterproof archive quality ink as used by Registrars and the Clergy for signing official documents. Supplied in 28.4ml (1oz) bottles at £6.95 plus postage and packing. Suitable for all makes of fountain pen. Please note: this is an iron-gall based ink (a traditional recipe for permanent ink). We recommend that you clean your pen with clean water prior to refilling or before storing away. Diamine Registrars ink permanent and waterproof 1234