A proper table tennis bat must have a red rubber on one side, and a black on the other to be used legally in competition. What’s the reason for this, and does it really matter which one you use on your forehand or backhand?
Why red on one side and black on the other?
It was many years ago that the ITTF brought in the rule that one side of the bat needed to be covered with red rubber, and the other side black. The main reason for this was that a lot of players used different rubbers on either side of the bat, some dramatically different, like antispin on one side and a fast spinny rubber on the other. The idea was that opponents needed to be able to anticipate what was on the incoming ball by the stroke played by the opponent, and it should not be down to guessing which rubber they used. Having the two rubbers different colours allowed opponents to see which rubber was used for which stroke.
These days a common question is why certain players, or even whole teams, always use one colour rubber on the forehand, and the other on the backhand. Are red and black rubbers, even identical brand and type, inherently different?
Well the consensus is that yes they ARE definitely different, but for some rubbers it’s much more significant than others… For Chinese tacky style rubbers for example, the difference is usually most obvious; the red rubber is a little less tacky, and the black is a little softer and tackier. The tacky surface slows the ball down a little, so this also makes the red a little faster than black. So you would chose the one that suits you better on the forehand. For a more spin based looping style game, a black rubber may well be a better choice to aid in generating spin. For more of a hitting / driving style game the red may be a better option, which will not only give you a little extra speed, but the red rubber is also a little less sensitive to incoming spin, which makes it more forgiving.
This difference is believed to come from the manufacturing process. The raw rubber used to make the rubber topsheets, is naturally tacky and black. The dye needed to make the rubbers red, makes it lose some of its tacky characteristics and softness. For some rubbers, the different characteristics are quite obvious. For example a black “729 Geospin Tacky”, one of the spinniest rubbers made by Chinese manufacturer “729 Friendship”, is a quite a lot tackier in black than the same rubber in red. Because players usually buy such a rubber for it’s great spin potential, the black is a lot more popular than the red.
For many Japanese or European made rubbers, most of which are inherently non-tacky (but grippy), the differences not really noticeable so the decision is not as important.
So in conclusion, the decision on which colour you use on which side does indeed make a difference, although many players are not even aware of this, and their decision is based on personal preferences, or is simply inherited from other players. For a more spin based game I’d recommend black on whichever side is used more to generate spin. For a more speed based game, red on your attacking side might be more appropriate.