In domestic cooking, bulk solids, notably flour and sugar, are measured by volume, often cups, though they are sold by weight at retail. Weight measures are used for meat. Butter may be measured by either weight (" lb") or volume ("3 tbsp") or a combination of weight and volume (" lb plus 3 tbsp"); it is sold by weight but in packages marked to facilitate common divisions by eye. (As a sub-packaged unit, a "stick" of butter, at lb g, is a "de facto" measure in the US)