What are the key quality differences between isomer-grade and solvent-grade mixed xylene?

What are the key quality differences between isomer-grade and solvent-grade mixed xylene?
Not all mixed xylene is equal. Solvent-grade material can contain over 50% ethylbenzene, which lowers dissolving power versus isomer-grade mixed xylene. This distinction matters in coatings: high-quality plastic and automotive paints require isomer-grade, while solvent-grade may suffice for less demanding applications. In nitrocellulose lacquers, aromatic hydrocarbons like toluene and xylene have much higher dilution ratios than aliphatic petroleum solvents—toluene's ratio versus ethyl acetate is 3.4 compared to 1.0 for petroleum solvent—making aromatics the preferred diluents. However, some manufacturers cut costs by using off-spec, low-aromatic xylene in formulations that should use isomer-grade, risking performance issues. Coatings producers should verify aniline point or mixed aniline point to assess solvent strength; lower values indicate higher aromatic content and better solvency.