This is a term for natural fats that spew from the inside of the leather to the surface. It can make the leather look like it has a milky film or a haze on it. Though rare, it is most often seen in Aniline leathers. This residue will wipe away with a cloth, but it will continue to reappear unless it is removed with this product. Applying Leather Master Spew Remover to the surface wipes away the spew and absorbs into the leather to lock remaining fat liquors inside the leather to prevent reappearance.