Egg cups signed Atch Chantal and Thierry Robert sandstone from Poncé sur Loir

Set of three pretty egg cups in sanded stoneware, with light gray and salmon pink enameling. They are signed by Chantal and Thierry Robert from the Atch workshop. The signature was made by hand hollow in the sandstone and not with a stamp as is often the case. I suppose these are objects that this couple of recognized ceramists created quite early, at the beginning of the 1960s, before have had a stamp made. They are in good general condition, no cracks, just a small chip on the enameling of one of them. They measure 10 cm in diameter at the level of the cup, 6 cm in height, and 4.3 cm in internal diameter at the level of the egg cup.