The ribbon noodles and the Bolognese partner
Tagliatelle is fresh pasta, rolled and cut from dough — not dried. Its rough surface holds sauce differently than dry spaghetti, which is why it is the official partner of ragù alla bolognese.
In Bologna, there is an exact unit of measurement for the width: 8 mm in the raw dough, equivalent to about 7 mm cooked, filed with the Chamber of Commerce. Italy takes pasta seriously — and the Bolognese are right.