When you purchase a lighting fixture, check the maximum wattage it will take. This is important because too much wattage produces excess heat and creates a fire hazard or damages the fixture. For safety reasons, never use a bulb larger than the maximum size specified. However, it is advisable to use the maximum size, because it will generally be more efficient. It gives more light per watt. You can always control the light with a dimmer. Many Thomas products are engineered to offer you the opportunity to use higher wattage bulbs. It's important to note that wattage is the indication of how much power a bulb consumes, not the amount of light it generates. To get the brightest light possible for your fixtures, look for the highest lumen rating for the wattage that your fixture is rated for. (Lumen - The amount of light a bulb produces.) For more lighting terms click here.