Copper (high cost; recommended for browning and sauces): This is a superior cookware material. Copper reacts with certain foods, so the cookware must be lined with tin or stainless steel. Never cook or serve in unlined copper pots or pans. Advantages: Exceptionally good looking; excellent heat conductor; durable. Disadvantages: Needs frequent polishing; any cracks or scrapes in the lining mean the cookware must be relined.