Good question, Steve.

As a Canadian, I have been cooking with weird measures my whole damn life. Old Canadian cookbooks use British measures, gills, pints and quarts, and modern cooks have to be alert to the fact that the pint in question is 20 fl oz Imperial and the quart is 40. You know you have one of these books when you notice that it does not call for cup measures, but half a pint.

Pounds and dry ounces are blessedly consistent, and professional recipes, especially for bread, are written that way. When the metric system hit us in 1978, we just converted, and Canadians of a certain age are very good at multiplying and dividing by 2.2.

But sometime in the 1930s the American cup, at 8 fl oz, invaded Canada, and the schizophrenia started. I particularly dislike bread recipes that use volume measures for flour; flour is quite variable enough without faffing about with filling your measuring cup JUST SO and then realizing that it's wrong anyway. Weighing out two pounds (or a kilo) of flour is far easier. Also, you don't have half a dozen measuring cups to wash after.

Butter is another ingredient often called for in volume measures when a weight measure is both easier and neater. One tablespoon of butter is half an ounce. How hard can this be?