The first video is of an art joranl, a lot of paintings and drawings in a moleskine. Watercolor, ink, acrylic, and a variety of other media are used. It's a lovely journal. (She really ought to wax her pages though.)
This one uses nothing but black ink, sakura pigma to be precise. He draws from life and makes no notes or observations but for the drawing. It's another style of journal. It's gourgeous. Blow it up big on your monitor and LOOK at that hatching.