Selvol 205, PVOH grades offer incredible versatility in one core product. In fact, it’s the most versatile PVOH product we offer. The key to working ideally with Selvol PVOH is finding the grade that suits your needs. Each Selvol PVOH grade varies in molecular weight and degree of hydrolysis. We generally express molecular weight in terms of solution viscosity. First, we classify the viscosities as ultra low, low, medium and high. We commonly denote the degree of hydrolysis as super, fully, intermediately and partially hydrolyzed.