Linear ethylene interpolymer blends are disclosed. The blends are made from components having a narrow molecular weight distribution (e.g. M.sub.w /M.sub.n .ltoreq.3) and a narrow composition distribution (e.g. CDBI>50%). The blend components in a blend can all have the same molecular weight but different comonomer contents, the same comonomer content but different molecular weights, or comonomer contents which increase with molecular weight. The blends have either M.sub.w /M.sub.n >3 or CDBI<50%, or both, and can be multimodal with respect to either or both molecular weight and/or comonomer content. The blends are generally free of blend components having both a higher average molecular weight and a lower average comonomer content than another blend component. The blends can have improved mechanical, physical and/or chemical properties.