Tennis racquets are now made with ultra-light materials

It's hard to imagine Roger Federer or Serena Williams pulling a wooden racquet out of their bag at Wimbledon, but they're not as ancient as you might think.

The centuries old sport of tennis has seen many changes in the size and shape of its racquets.

Curved heads, square heads, triangular heads - players have tried just about every variation down the years to try and hit that ball as sweetly as possible.

But the really exciting changes came during the late 20th century.

String info Early racquet strings were made from animal gut. Some of the best ones still are today, but they're mostly made from synthetic material The tension of the strings on a racquet is almost as important as the choice of frame. High tension in the strings gives more control and spin, while less tension equals more power Top players usually have their racquets restrung after every match

Tennis technology took off in the 1960s, when Wilson developed a revolutionary racquet called the T2000.

Made of steel and with a round head, the T2000 was lighter and moved quicker through the air than its wooden contemporaries.

American legend Jimmy Connors used it for most of his playing career, and it helped him win Wimbledon in 1982.

In 1968 Spalding launched an aluminium racquet, called The Smasher.

Aluminium is lighter and more flexible than steel, but stiffer - and therefore less accurate - than wood.

Because of this, most of the top players still preferred to use wooden frames - and a decade later they were still in use.

They certainly worked for Bjorn Borg. The Swedish legend won 11 Grand Slam titles in the 1970s and 80s using a wooden racquet.

In 1982 Dunlop launched the Maxply McEnroe - a racquet that combined the accuracy of wood with the increased power and durability of fibreglass.

New balls, please 1902: Each ball was hand sewn and no two were alike. Balls were made from rubber with wool cloth covering 1929: Balls made using a vulcanising process and by cementing the cloth onto the core 1937: Special refrigerated container is introduced to maintain the correct temperature of the balls 1954: Nylon-Armour introduced. This was a coating on the covering to improve wear and prolong playing characteristics 1986: Yellow balls are used at the Championship for the first time to make visibility easier for players, spectators and the television audience 2002: The ball is treated with a water repellent barrier called Hydroguard. Great for the British weather!

The racquet was a big success, but the emergence of a new material meant the days of the wooden frame were numbered. The last wooden racquet appeared at Wimbledon in 1987.

The new material in question was graphite.

Still used by the stars of today, graphite is a form of carbon fibre that can be used to make racquets on its own, or combined with other materials such as fibreglass.

Graphite racquets have all the advantages of wood with none of the drawbacks.

They are strong, light, powerful and durable - and they can always be relied upon to hit the required shot.

To make this easier, oversize racquets were introduced in the early 1980s.

As the name suggests, the racquet heads are larger which means they have bigger 'sweet spots'.

The downside is they're harder to control, and better players usually choose smaller head sizes.

Power play

For many, the one thing that makes today's game different from 20 years ago is the huge increase in power.

Technology has undoubtedly played a big part, in particular the development of the wide body racquet.

Wider than a traditional racquet, this design provides added power but reduces flexibility. It's a hugely popular racquet, but not everyone is impressed.

Past tennis greats like John McEnroe have complained that the modern game is too reliant on power and boring to watch as a result.

The likes of Andre Agassi, Roger Federer and Maria Sharapova might just disagree!