I am fortunate to receive a bundle of washi paper from my friend. The washi is 50 years old, and made by one of the master paper makers in Yoshino, Nara. There is a Japanese webpage of the maker: http://kuzunosato.jp/self/fukunishi.html
I transferred my new drawing onto the washi. Drawing on it with sumi brush was smooth and very nice.
Next step is to add textures and colors to the drawing on computer.