This example is from Wikipedia and should be reused underneath a CC BY-SA license. They can be sculpted into many shapes throughout this process, sometimes resulting in deep thumb-print like indentations on their surfaces identified as regmaglypts. From Wikipedia References in periodicals archive ? Sculpted via the internationally-acclaimed JOOheng Tan https://sculpted-md-lakewood06936.blogdigy.com/sculpted-md-lakewood-an-overview-55464601