Karol Tabaka, the artistic creator of the commemorative stamp, used his design to depict three athletes - an American football player, a kick boxer and a speedway racing driver - all in motion. 

In doing so, he chose to display three of the four invitational sport disciplines chosen by the host city Wrocław to be added to the usual line of the Games’ sport disciplines, with indoor rowing completing the quartet. 

A "First Day Issue" envelope will also feature a picture of the newly-renovated Olympic Stadium, host venue to American football and speedway.

"For us it is a great distinction, because we know that commemorative stamps of this time are only issued on the most important occasions in our country," Marcin Przychodny, President of the Wrocław 2017 Organising Committee, said.

Wiesław Włodek, vice-president of the Polish Postal Service Board, added: "The Games are a very important international event and a truly exciting sporting experience.

"We feel that issuing this commemorative stamp will allow us to contribute to the prestige of the Games and it can serve as a unique addition to the campaign to promote Wrocław and Poland.

"It is also a great opportunity to promote the non-Olympic sport disciplines and perhaps in the future help them be added to the Olympic programme."

The Polish Postal Service has also issued a special card commemorating the 2017 World Games.

Designed by Maciej Środa and Filip Król, the card is due to be issued with a limited circulation of 2,800 and can be purchased at Wrocław 1 and Wrocław 32 post offices.

A special exhibition is currently open to the public in the Postal and Telecommunications Museum in Wrocław.

Named "10. Światowe Igrzyska Sportowe The World Games Wrocław 2017", it includes more than 300 miniature works of art presenting almost all the sport disciplines which will be part of the 2017 World Games.

The exhibition is due to be open until August 13, 2017.

Those interested in purchasing stamps and other commemorative items can do so in each location of the Polish Postal Service as well as online here.

Around 4,000 athletes from 31 sports and more than 100 countries are expected to participate in Wrocław from July 20 to 30.

A record 111 countries are due to compete, with the Games featuring sports and disciplines not on the Olympic programme.

The number is eight more than the previous highest turn-out for the event in 2013.