My favorite inks are Noodler's Bulletproof Black and Lexington Grey...it's a love-hate relationship, though. I bought myself some Lamy Safari fountain pens last year for my birthday (?) and the inks were highly regarded by other sketchers and Moleskine enthusiasts. They are waterproof on cellulose materials and wash off of others, making them good for mailing addresses, checks, important signatures and pen and ink sketches...if you're patient. Those who know me know that "patience" isn't my strong suit. If the conditions are humid, it takes a while to dry enough not to smear or run when painted over. I love to write and draw with it and the pens, so, I wait.
Last night, I got out my bundle of Sakura Pigma Micron pens, my first favorite pens before I got the Lamys. I'll carry them around for a back-up when I'm out and don't want to wait for the ink to dry. In the meantime, I'm going to check out my sketchbook papers, maybe the sizing is interfering with the ink absorption? Maybe some of the paper isn't cellulose? I used two new types in this sketchbook, made for Utrecht by Canson, I think. In the process of testing my pens (there were some older ones in the bunch), my kids decided they liked them, too, my daughter wants her own, to buy with her Christmas money. We'll make a pilgrimage to Utrecht this weekend...and maybe stop off at Creative for a tube of Daniel Smith watercolor along the way!