Good tomato sauce can be made from fresh or canned tomatoes. When fresh tomatoes are at their peak, it may be a good idea to use them exclusively. At other times of the years, good-quality canned tomatoes are a better choice. Plum tomatoes, sometime referred to as Romas, are generally preferred for tomato sauce because they have a high ratio of flesh to skin and seeds. Fresh tomatoes may be skinned and seeded for sauce, or they may be simply rinsed, cored, and quartered or chopped. Canned tomatoes come peeled and whole, crushed or pureed, or a combination of the two. Tomatoes paste is sometimes added to the sauce as well.