Xylene is used as a solvent. In this application, with a mixture of isomers, it is often referred to as Mix Xylene, xylenes or xylol. Solvent xylene often contains a small percentage of ethylbenzene. Like the individual isomers, the mixture is a colorless and highly flammable liquid. It is a common component of ink, rubber, and adhesives.In thinning paints and varnishes, it can be substituted for toluene where slower drying is desired, and thus is used by conservators of art objects in solubility testing. Similarly, it is a cleaning agent, e.g. for steel, silicon wafers, and integrated circuits. In dentistry, xylene can be used to dissolve gutta-percha, a material used for endodontics (root canal treatments). In the petroleum industry, xylene is also a frequent component of paraffin solvents, used when the tubing becomes clogged with paraffin wax.