A water-immiscible marker is dissolved in polyethylene glycol or other suitable carrier, and the marker so dissolved is added to a waterborne composition which is used as an additive to a waterborne or water processable composition. Subsequently, the marker is either extracted with a non-polar solvent or detected by means of a surface spot test. From the non-polar solvent, the marker is extracted with an acidic aqueous solution or an alkaline aqueous solution, depending upon the marker, and color-developed. Likewise, a surface spot test can detect the presence of the marker by, if necessary, first softening the marked surface to be tested either chemically or by thermal means, and developing a color with a color-developing reagent placed on the exposed surface. Applications can include the marking of paint, coatings, wax emulsions and water soluble/dispersable additives commonly used in water based applications, e.g., cement additives.