Bread is usually sold by weight. You can sometimes get the baker to sell you half of a large loaf (metá). The cheapest bread will be Pane comune, ordinary bread made from a "lean" dough--flour, water, yeast and sometimes salt (saltless bread is commonly found in Tuscany).
But if you are trying to make sandwiches for a picnic, you would order several panini, or one panino. Note that the word "panino" can refer to a finished sandwich, or just the roll.


