An old-fashioned gall-based ink that once dry is waterproof and of archival quality. It will not fade!. It is only available in blue/black. As it is gall based, it will at first appear to be a blue ink, but will darken as it dries and eventually, after 5 or 10 minutes will be a deep blue/black colour. It is available in 30ml bottles, or in international sized ink cartridges, in boxes of 18. Due to the acidic nature of this ink, it is advisable to flush your pen through with cold water before between fills.