It is with great sadness that I heard about the recent passing of Zvi Shkedi, a member of this forum, who was the inventor of "Dyo Lonetzach", a revolutionary type of ink that is waterproof and does not crack or flake. His many articles and discussions can be found on this forum by searching his name in the search bar on this page. Here is some info on his life and achievements, which can be found by clicking the link below. https://collive.com/zvi-shkedi-73-obm/ I hope his ink continues to be produced, as I have personally found that the Stam written with his ink are easier to check - as there is no cracking or bruising apparent in the ksav, particularly on the folds of the shel rosh in tefillin, which, when written with regular ink often need touch ups as they age (particularly if the tefillin are checked often). If anyone has any personal stories or further info about the production of Dyo Lonetzach, please feel free to post. Boruch Dayan Hoemes.