A grilling plank is the board used to hold food while it is being grilled, that serves to provide a moist and somewhat smoky flavor to the food. This procedure was introduced hundreds of years ago as food was grilled over open fires and held by wooden planks. As it evolved, a wide range of woods were introduced for use as wood chips placed among hot coals and as planks for use above the hot grilling flames. Hardwoods are much better than softwoods because hardwoods take more heat longer and they also add more flavor to foods through the smoke that is produced as the wood is burned. Softwoods have a tendency to deterioriate by burning more quickly and adding only a slight flavor to the grilled foods. Wood planks can be purchased at lumber stores, hardware stores, food stores, and a variety of speciality kitchen stores. When selecting and depending on the size of food being grilled, attempt to find boards that are approximately 12 to 16 inches in length, 6 to 8 inches wide and 1 inch or so for thickness. The wood should be untreated to keep any infused chemicals from contaminating the food. Prior to grilling, soak the wood plank for 4 to 8 hours or longer, keeping it totally immersed in water. When ready to use, remove the plank from water and just before placing it on the grill, use a pastry or grill brush to apply vegetable or olive oil to the side that will hold the meat to keep it from sticking to the board. Place the board in the center of the grill over a medium heat and place the food on the board. Food placed on a plank is grilled to the same temperatures as is customary for the food being prepared, making sure it is completely cooked and reaching temperatures that make it safe to eat. Be prepared with a sprayer bottle of water to extinguish any flames that ignite the board as the moisture in the board dries out and the board begins to darken along the underside and the edges. If any grilling or barbecue sauce is to be applied, this can be accomplished during the last 20 to 30 minutes of the grilling process. When the grilled food is finished cooking, remove the food, turn off the grill and allow the board to remain on the grill to cool down before handling. Foods such as meat, poultry, fish, and vegetables are all good choices to consider for grilling on a plank.