After doing several “reverse scrimshaws” – scrimshaw on a dark material where the stipples/incisions are filled with a white pigment, I found they looked kind of dull. From experiments a couple of years ago using “Pearl-Ex”, I knew mixing it into the pigment only made a slight difference.
This time, I coated the surface with an acrylic paint (oil paint should work the same), then wiped it off while it was still wet. With a Q-Tip, I lightly brushed some of the Pearl-Ex (micropearl – smallest white particles I was able to find) onto the surface then wiped it off so the particles would adhere to the wet paint in the stipples while the rest would wipe away. It made a big difference no matter what angle you hold the piece now. Available at many local art supply stores and at Amazon.com (Pearl-Ex Micropearl)