Presented in roughly reverse chronological order: 

1. Gouache & ink on Yupo (a polyurethane paper)
2. Non-waterproof ink on Yupo  
3. India ink on a hot press paper
4. Non-waterproof ink on hot press paper
5. Goache & india ink on hot press paper
6. India ink on cold press paper
7. India ink on cold press paper
8. Goache & india ink on cold press paper
9. Goache & india ink on cold press paper 

Cold press papers are fairly rough, while hot press is pretty smooth.  The smoother the paper, the more easily the pen and paint move around as you apply them. The Yupo paper is at the extreme "smooth" end of the spectrum.  It's basically just a sheet of plastic that's been treated to have a little bit of tooth for the media to grab onto and stick to. Not absorbent at all, and it doesn't buckle when wet, which is actually pretty nice.  Definitely a weird and interesting paper to work with.

Some of the ink was applied with india ink marker pens, some with classic dip pens, and some as a wash (with a paintbrush).  The lines on 8 & 9 were done with only the markers; the others are mostly done with the dip pens, with the markers used to fill in little bits here and there.  The dip pens are much looser in their application than the markers, and of course the wash is loosest of all.  I haven't used dip pens in over 15 years, so it's been fun re-learning how they work. 

All of these use the same stencil, which I made myself.