Cupping: As a canvas expands and contracts, the paint layer is forced to crack, forming a network or craqueleur.  This is expected, given the inherent nature of the materials.  Oil paint cures to a rock-hard state, while canvas is and remains hygroscopic.  Over time the cracked paint layer may form concave islands.  The technical term for this condition is cupping.

Cupping: As a canvas expands and contracts, the paint layer is forced to crack, forming a network or craqueleur.  This is expected, given the inherent nature of the materials.  Oil paint cures to a rock-hard state, while canvas is and remains hygroscopic.  Over time the cracked paint layer may form concave islands.  The technical term for this condition is cupping. Cupping: As a canvas expands and contracts, the paint layer is forced to crack, forming a network or craqueleur.  This is expected, given the inherent nature of the materials.  Oil paint cures to a rock-hard state, while canvas is and remains hygroscopic.  Over time the cracked paint layer may form concave islands.  The technical term for this condition is cupping.