I have been using pigmented epoxy on most of my kayaks lately. Normally I use artists pigments. For black I have come to prefer iron oxide, as the most opaque of those I have tested and one with less effect on viscosity than most other. I add as much pigment as possible without losing the brushability of the mix (not very scientific, but quite convenient). On my latest kayak I used this mix on all layers, including laminating – I experienced no problem controling the wetting-out process, and have not noticed any disadvantages on curing or laminate stability.

Bjorn