The easiest to get started and smoothest flowing paint pens I've tried, and I've tried a LOT. These Vickay paint pens are oil based paint pens, have sturdy pen barrel and durable acrylic tip, and even includes 3 extra replacement nibs!.The ink is acid-free, quick drying, non toxic, and both water and fade resistant. The ink was very easy to get started flowing, and once started, never gushed out or had any inconsistency in amount of ink flow. They can be used to write on just about anything, making them the perfect paint pens for any DIY or craft project without the worry of ruining your artwork with splotches of paint that gushed out without warning. I highly recommend these paint pens, the quality and efficiency in smooth, even writing is far better than most other paint pens I have. Highly recommend.