Confusion about significance of titanium in ink for Vinland Map

Hi Izyat, thanks for the question! The author makes some contradictory statements in this stimulus. He uses the rarity of titanium in ink during the 15th century to claim that B36 is now strongly supported to have been written by Gutenberg. The author then goes on to say that titanium in ink was found on another item, the Vinland Map, and based on this, it is possible that this map is from the 15th century as well. So the author claimed that titanium in ink was so rare in the 15th century that we can narrow down B36 to a single source, but then the Vinland Map could have possibly been used by someone else in the 15th century. The author uses the rarity and lack of rarity of titanium in ink to prove different points. Quite odd. To answer your question specifically, I do not think that titanium in ink used for the Vinland Map necessarily means that titanium in ink was common at the time, it just means that it was available enough to be possible that someone else used it. Hope this helps!

Couldnt it be the case that the ink was still extremely rare and was only used by 2 people out of hundreds of thousands? I still dont see how he is suggesting it is common in the latter instance...