Spéranza Calo-Séailles
Spéranza Calo-Séailles or Elpís Kalogeropoúlou in Greek; Ελπίς Καλογεροπούλου (17 May 1885 – 18 February 1949) was a Greek painter, inventor and opera singer. She is known as a singer and artist, but she invented a type of decorative concrete which went under the name Lap. Life. Calo-Séailles was born in Constantinople in 1885 where her name was Elpís Kalogeropoúlou. She first attracted attention as a mezzo-soprano and she acquired a patron who was willing to support her development. In 1923 she invented a type of decorative concrete and a patent was applied for in  June 1923. The new material which went under the name Lap. Her invention was developed by her and her husband who was a Sorbonne Professor. In 1929 her Lap materials was used in the construction and decoration of the in Rheims. They provided a challenge when the building was renovated in 2012 and the panels were replaced with GR In 1930 she was creating work using Lap with Tsuguharu Foujita. Foujita made her portrait and also created several works in Lap at the company's base in Antony. Calo-Séailles died in Paris in 1949.