Relief is a sculptural technique dating back to ancient times. Relief sculpting gives the impression that the sculpted images have been raised above the background plane, when in reality the flat background surface has been cut and lowered leaving the unsculpted elements to appear raised.
The two main types of relief art are high relief and low relief or bas-relief. High relief is where more than 50% of the sculpture protrudes from the background. Conversely, in low relief, the protruding elements have a shallow depth; like on coins.
Traditionally, relief sculpting is to cut into and lower a flat surface, usually stone or wood. But, it also includes the technique of adding depth and texture to (on top of) a flat surface giving it a three-dimensional (3D) look. Many different materials can be used to achieve this 3D affect.
Khaleel’s relief art is mixed-media fusing sculpture and painting. His technique is to add volume and dimension to canvas in mostly low relief with some high relief elements. He achieves his three-dimensional look using marble dust mixed with zinc oxide, hardeners, adhesives, and oil paints.