Board Thread:FAQs/@comment-36926079-20190801193714/@comment-26397825-20190803014955

Perhaps it's the one that's the rarest in terms of availability for regular Huntsmen. We've seen it used everywhere in appliances (which would be premade in factories) and infrastructure (which would be ordered by large companies and the governments), but not so much when it comes to Huntsmen and their weapons.

Maybe Atlas simply doesn't release much of it onto the general Huntsman marketplace for everyone to use, and instead keeps it for big orders such as what comapnies would do. In that case, it would be the 'rarest' type of Dust for Velvet to find, since it simply isn't available for her.