The plates of a panini grill can either be smooth and flat, or they can have grooves cut in them that produce attractive grill marks on the finished products. Units with grooved plates are typically called panini grills and are used primarily for cooking meats and fish, though they can, and frequently are, also be used to grill sandwiches as well. Many units even give you the option of having mixing smooth and grooved plates so that you can sear just one side or cook different products on the same machine. If you are going to be creating a large quantity of panini sandwiches, you may want to consider getting a grill with a split top. Split-top panini makers essentially have two grills side-by-side. These models are usually larger than full-top units, so you will want to check and make sure there is enough countertop space available. Lastly, many panini makers require special voltages and a dedicated circuit, so it is important to make sure that model you are interested in is wired to match your establishment and that you have enough space in your electrical panel.