I found these refillable paint marker pens at a graphics store in Honolulu. I plan to fill them up with Createx airbrush paint and use them for my pin-lines. Here is a clip on how to fill them up:https://www.youtube.com/watch?v=kW_K1EcpQzY. Here is a site that carries the markers: http://www.utrechtart.com/Montana-Acrylic-Empty-Refillable-Paint-Marker-MP-19907-036-i1017150.utrecht and http://www.montana-cans.com/products/Marker_Inks/2. I am playing with mine tonight. I am thinking about mixing custom colors.
I have no affiliations with the company but I wanted to share this with the crew!
D