A specific combination of two different polyolefin clarifying and nucleating agents, namely bis(3,4-dimethyldibenzylidene) sorbitol (3,4-DMDBS) and bis(3,4-dichlorodibenzylidene) sorbitol (3,4-DCDBS). Such a combination surprisingly provides improved clarification comparable to polypropylene articles and formulations, better than DCDBS alone and equivalent or better than DMDBS alone. Such a combination of compounds thus permits the utilization of a new additive for the purpose of modifying polyolefin properties, such as polypropylene clarification and nucleation. The inventive combination may be introduced within any polyolefin composition, again preferably polypropylene, which may then be molded into any shape or form. A method of producing a polyolefin plastic utilizing the inventive combination of compounds is also provided.