There are generally two types of stains. One type is caused by water-based substances like food and body fluids, while other is caused by oil-based substances. Inks can fall into both categories: those that are wet side, water removable and those that are dry side, solvent removable. Specialized chemicals are used to accelerate the ‘freeing’ of certain stains and these chemicals are generally specific to wet side and specific to dry side spotting and cleaning. Extreme care should be used in applying chemicals to fabrics. Always use a test area which is inconspicuous to see if color change will occur before proceeding to the stained area.