Inverted rubbers consist of a 'topsheet' (the red or black part) and a 'sponge' (usually cream, yellow, orange or red coloured) which are usually sold glued together already. Many inverted rubbers come with several different sponge thicknesses (eg 1.5mm, 2.0mm or MAX) which can be selected. Thinner sponges give you better control of the ball, and allow you to feel the ball onto your bat better. Thicker sponges can potentially give you more spin and spin at the fast end of power loops, so they are more suited to the more offensive type players. Generally 2.0mm and above is chosen for the more offensive players, whereas thinner sponges are chosen for the more all-round or defensive players.
Inverted rubbers (also commonly referred to as 'Reverse rubber' or 'Smooth rubber' as it's smooth on the outside), is currently the most common used rubber, used by powerful attackers through to talented defenders. These rubbers are can generate the maximum amount of spin. Inverted rubber's versatility allows an extensive variety of stroke play. Offensive rubbers generate high levels of speed for powerful strokes and high spin, All-round rubbers generally have more control allowing you to play both an offensive and defensive style game, whilst Defensive rubbers are generally the slowest, allowing you to generate or manipulate the spin and control the pace of the game. 'Glue Effect rubbers' are a special type, generally for the more offensive style players, where tension is built into the rubber to give it extra speed (and sometimes extra spin) and a unique feel, although these are generally not recommended for beginner or developing players.