Although the U.S. flags placed on the Moon by NASA astronauts were not designed specifically for space travel, sources differ on where exactly they came from. Some sources say that the flag that went to the Moon with the Apollo 11 mission was purchased at Sears by a secretary on her lunch break. Although that story is probably apocryphal, it may have some truth to it.
Dick Lattimer, author of All We Did Was Fly to the Moon said the flag was made by Anin & Co., which manufactured the flags sold by Sears and those in the Government Stock Catalog. Jack Kinzler, chief of the Technical Services Center at NASA's Lyndon B. Johnson Space Center in Houston, wrote in his 1969 notes that the 5-foot by 3-foot (1.5-meter by 1-meter) flag was ordered from the Government Stock Catalog for $5.50 (USD).
Historians know for sure that the Apollo 11 flag was made of nylon. NASA technicians sewed a hem at the top of the flag so it could be placed on the crossbar of a flagpole for planting on the Moon.
Putting a flag on the Moon: