Fitted baseball caps, suited to a particular headsize, lack an adjuster. The cap is normally sewn in six sections, and may be topped with a matching fabric-covered button on the crown. Metal grommets or fabric eyelets are often sewn or attached near the top of each of the six sections of fabric to provide ventilation. In some cases, the rear sections of the crown are made of net-like mesh material for extra ventilation. The bill is typically stiffened by a sewn in piece of paperboard. Baseball caps are made of all types of material and shaped in various styles for different purposes. Major league baseball players wear classic-style caps made of wool (or, more recently, polyester) with their team's simple logo and colors; the logo is usually embroidered into the fabric. Caps used by players may sometimes have sunglasses attached to the peak that can be flipped down when the player must look into the sky, but kept flipped up at other times.
