Like spaghetti, spaghettini is a long pasta. Of the many forms of long pasta, bucatini is thicker with a hollowed out center, spaghetti is solid and thinner, spaghettini is thinner yet, then comes capellini and angel hair is the thinnest. Because spaghettini is thin, it requires little cooking time and is easily over cooked. Be guided by the timing suggested on the pasta packaging (usually about 8 minutes after the water returns to a boil) and test carefully and often. Spaghettini is usually accompanied with light, often seafood based sauces.