Guidelines

• Although most any cookware can be used on a glass cooktop, some works much better than others. Avoid cheap, thin-walled pots and pans. They warp easily and don't transfer heat evenly from the flat surface of the cooktop to the contents of the pan. Glass cookware may crack over time because of the rapid changes in heating on a glass cooktop.
  
  Some manufacturers recommend against using cast iron cookware for two reasons. Cast iron is heavy, and too much weight on the cooktop can cause it to crack. Also, because cast iron is heavy, the cook may tend to slide it across the cooktop, rather than lifting it. This can scratch the glass. Cast iron can safely be used as long as you exercise caution.
  
  Use cookware with a flat bottom. Smooth, flat bottoms make even contact with the surface of the stove and provide more even heating. High-end products such as Calphalon and Le Crueset cookware offer the fewest opportunities for scratching or cracking the surface. Heavier pots are less likely to move when you're boiling water or other liquids.
  
  

Things to Avoid

• Don't shake pots or slide any cookware across a glass cooktop. Pans with rough bottoms can scratch the surface. Pots and pans with a ridged or step-cut bottom are not recommended for this reason.
  
  If you regularly use a water bath canner, buy a separate heating element or a side burner for your barbecue grill and use that instead of the glass cooktop. Very heavy pots filled with liquids can crack the cooktop. The same rule applies if you're a home brewer.
  
  Plain aluminum pots can leave a residue. Don't use pots with a painted bottom. Over time the paint may transfer to the cooktop.
  
  Traditional round-bottom woks, even used with a ring, won't perform well on a glass cooktop. If you enjoy cooking with a wok, find one with a flat bottom and flared sides.