Here are a two pages from my black paper sketch book. I was very excited to learn about the possibility of using white ink in my rapidograph pen. I was very pleased with the effect, but it required a lot of patience since rapidograph pens can take several minutes to get the pen to release the ink. Then, I needed to learn to draw sloooowwwwlly, so that the lines don't break up into light, textured lines.
The drawing on the left is a portrait of my grandfather, Frank, or as I called him Pop Pop. Unknown to me at the time I created this drawing that he would pass away a few hours later. The drawing on the right has a portrait of my cat Pheobe. The short pen strokes of fur worked very well with the white ink/radiograph pen.