Dr. Ph. Martins (facebook) is a brand of the inks from USA company Salis International Inc. They have been making art products for more than 80 years. Other than black, they offer other colours as well.
The Bombay Black India ink is sold in a 1oz (30ml) bottle. The small glass bottle comes with a dropper.
Here's the label that says it's lightfast, waterproof, pigmented, smooth, non-clogging, non-toxic and holds a line without spreading.
Since it's pigmented, it's not safe for use in fountain pens.
The opening of the bottle is much smaller than other ink bottles I've seen. Be careful not to damage your brush when trying to fit into the opening. Pictured above is a size 6 brush.
The Bombay Black is an intensely black India ink. I just love how dark it is.
It dries relatively fast, and it dries to a neutral tone. Once it's dry, it's permanent and doesn't smudge or rub off easily.
It holds up to erasing well, but with heavy erasing some ink does come off. On a scale of 1 to 10, it's probably 9 for it's resistance to erasing.
It's able to create sharp lines without feathering. This is true even on lousy paper and I'm quite impressed. It can hold the edges well even on newsprint paper, although if you leave the tip long enough it will feather of course.
It has good covering strength and is not too blotchy when used to fill large areas.
The Bombay Black is waterproof.
Click for a bigger view
The picture above compares various brands of black ink. Top half of the square's a single layer wash and the bottom has a double layer wash.
Dr. Ph. Martin Bombay Black is a solid performer as an India ink. Only downside is it can come off slightly during heavy erasing but not a serious issue. It's definitely good enough for comic inking for its intense black.