Does everyone know about this stuff? Because it's amazing! Just add a bit to the fabric ink, and no need to heat set.
The bottle advises adding 2.5ml to 250ml of ink. Please do check my maths, but I've worked it out at 3 drops per tablespoon (using metric drops rather than medical drops, whatever that really means, and just because 1/20 seems like a friendlier fraction than 1/12).