Has anyone of you used Sailor’s nano ink for sketching? What are your experiences of it? Can you use it with a watercolour wash without the ink dissolving? How long does ir have to dry before adding the wash?

I have a bottle but have not used it much. When brushing over a line with a wet brush it makes a grey wash.

I have also been thinking about if nano particles can be hazardous. I have heard that people working with it in industries must wear protective clothes not to come in contact with it. A few years ago there was a diskussion about it in media as it was being used for several purposes and was said to be hazardous.