I have a sketch on canvas that I want to paint, and read something in an art book that made me think that I could treat it like one of my little sketchbook sketches: darken the important lines, then give it a wash of acrylic paint for color and modeling.

However, to do that I need to find an ink that won't bleed through (I've had a bad experience in the past), so I did a little test strip.

Left to right: Black acrylic, silver ink, Calli, Dr. Martin's Spectralite, Dr. Martin's transparent watercolor, Higgins #44685, T-100 drafting film ink, Perfect Opaque Liquid, Higgins Black Magic, Parker Super Quick, Speedball Super Black, Speedball pigmented acrylic, Sharpie (thin and regular), Pitt, Micron, Bic

Top to bottom: water, acrylic glaze, white acrylic blended into black, transparent acrylic.

The winner, for my purposes is Speedball Super Black (no bleeding, no smearing, some showthrough under opaque paint, easy application (crowquill dip pen), with Micron as a close second.