When multiproduct plant economies exist, plant size and diversity decisions are closely linked. The disadvantage of small plant size can be offset by product-packing. The paper shows that within 4-digit industries, larger plant size is associated with greater product diversity. Then a cross-sectional regression at the 4-digit level indicates that Canadian plant size relative to an estimate of US MES is related positively to industry measures of average plant diversity. This suggests that inherent plant scale disadvantages in small economies such as Canada are offset by product-packing.