Could you post a picture of a writing sample .. how it looks once dry. If the bottle is open of course
Is did once store a small amount in a Metal container and forgot about it. It completely Changed colour and was useless. The ink became sort off brown.Very interesting! Not familiar with the brand, but I suspect it's what's called an "iron gall" ink, which is waterproof, indelible, and will change color from a blue-black to a black as it dries and ages. Before loading it in a pen, you should double-check to make sure there's no sediment, sludge, or mold that could contaminate a pen. Iron gall inks can be a little fussy and mildly corrosive, so they shouldn't be left unused in a pen for more than a couple of weeks to avoid clogging.