The old loaf sugar came from wooden molds that were conical shaped. Thus they themselves were cone shaped and a cook would have to pound the loaf to get loose sugar for cooking. They had to use special tongs/cutters to break of pieces of the loaf for consumption.
The Frugal Housewife. from 1830 says this about its wrapping,
“The purple paper, which comes on loaf sugar, boiled in cider, or vinegar, with a small bit of alum, makes a fine purple-slate color. Done in iron.”
2006-08-03