(Quoted from Keith Stevens and Impressions Magazine. Full article here.)
Reducers reduce the viscosity or thickness of an ink when you feel the need to make an ink creamier or easier to print. Most inks come ready for use right out of the container and if needed, inks can be easier to use just by stirring it up for a few minutes. But at times, a reducer can help. Try stirring it first and you may find that that alone may do the trick.

Click here to read the full article