Can you tell me more about any powdered inks that you know about? I only know about the
Thistle Blue/Black that was offered years ago and is now gone, and about someone who was going to sell powdered inks some years ago, but I think the project got derailed.
Powdered inks really save on shipping. I can buy distilled water nearby for a lot less than it costs to ship some with dyes in it .
Pretty well all the vintage powdered inks (Webster Diamine Blue-Black (iron-gall), Simpson's Powdered Inks, Thistle Blue-Black, Angus Blue-Black) have all disappeared from eBay. Very occasionally a set of pen holders, nibs and a packet of Thistle Blue-Black appears on ebay vendor Vanviking's page.
A manufacturer has been trying to do something with new powdered inks. It appears that the problem is complexity. The vintage inks were very simple in formulation as they were designed for dip pens. The modern inks are designed for fountain pens and need extra components like flowing agent and biocide which did not mix evenly in the batch of powder. More work is still ongoing.