The main raw material for the production of polyolefin films is PE-LLD, whose newest types, synthesized with metallocene catalysts, allow a wide range of variability and predictability in the molecular structure of the polymer, including the length of the side chains. This strongly influences the properties of the polymer and the films made from it. In the following, we will describe how these properties are affected in commercially available ethylene/α-olefin copolymers with short side chains and what can be expected when using PE-LLDs with extremely long side chains.