From the reference box #61
#61 - 4 British stamps commemorating Racket Sports; Lawn tennis (8 1/2p), Table tennis (10p), Squash (11p), Badminton (13p). Issued on the 12 January 1977, this set was designed by Andrew Restall, but in a totally different, much bolder illustration style to this set he designed in 1983. I personally prefer this more graphic style with the silhouetted figures and bright, blocks of colour, although I'm not sold on the colour combinations.
The best thing about these stamps for me though, is how they show the paths of the balls and the shuttlecock - it's really interesting to track their movements throughout a game and to see which games are faster as their paths are more direct with less curves and more bounces.
Take a look at more reference box items here.