This report is about Optimization of Hansens Solubility Parameters. It is about examining which of the methods for evaluating hansens solubility parameters works best. Experiments are made for HDPE and ABS polymers. After the polymers contact with solvents, they are being examined in 4 different methods. Tensile strength reduction, hardness, observation and swelling. The results of the experiments are evaluated, and a conclusion are made with for and against each of the methods. Finally, a possible optimization of the methods is given.