Specific low density polyethylene articles that exhibit improved physical characteristics and other benefits over previously made articles produced by less efficient means are provided. Such articles require the presence of saturated or unsaturated bicyclic dicarboxylate nucleating agents that impart increased crystallization temperatures, permit lower manufacturing cycle times, and, most importantly, cause a drastic reduction in warpage at quick cooling times during production. These resultant articles thus can be produced more efficiently with reliable low-warpage characteristics.