Linear low density polyethylene of ultra low density

A heat-sealable LLDPE for packaging is prepared by employing conditions, catalyts, and an amount of C₅-C₁₂ aliphatic alpha-olefin comonomer(s) sufficient to produce a density in the range of 0.87 to 0.918 g/cc whereby a narrow molecular weight copolymer is produced which has a low I₁₀/I₂ ratio and a z₁/z₀ value which is in the range of 3.5 to 7, along with a numerical value which is not greater than the sum of (62.4 - 63.7·density), and also exhibiting good heat-­seal strength and low concentrations of hexane-­extractables. Preferably, the comonomer is at least one straight chain C₅-C₈, most preferably octene-1. The density is preferably not more than 0.915 g/cc. Due to its strength, good heat-sealability, and low levels of n-hexane extractables, the material is ideally suitable for packaging food, but also has other utility.