When I visited Japan last year, I loved browsing around little stationery shops where you could try out more pens and colors than you could ever dream of. I ended up purchasing some Deleter Neopiko Line 2 pens in 0.05 width, and loved them so much that I used them in all of my hand written cards, invitation packaging cards, and wedding client cards for the past two years.
The Neopiko Line 2 pens have acid free pigment ink which is also waterproof. But, my favorite part is that they draw an extremely thin line! They are definitely the thinnest that I have ever seen compared to pens that you can commonly purchase in the US. One downfall of these pens though is that you have to be a little bit delicate when writing with them, because the pen point is very small. One push too hard, and the tip is gone!
My brother-in-law, Paul, and his wife went to Japan earlier this month and I had asked them to get me a couple of Neopiko pens if they happened to see them in their shopping/browsing. When I saw what they had gotten me, I think I let out a little squeal...
They got me five Deleter Neopiko Line 2 pens, in .1, 0.05, and 0.03 sizes. I couldn't believe that there was one that was thinner than what I used before! It was such a nice surprise to get some extras, and I'm so excited to write with them in all of my future cards.