This example is from Wikipedia and could be reused less than a CC BY-SA license. They are often sculpted into a variety of shapes during this method, at times causing deep thumb-print like indentations on their surfaces termed regmaglypts. From Wikipedia This example is from Wikipedia and could be reused https://sculptedmdlakewood58135.mybuzzblog.com/16229959/sculpted-md-lakewood-can-be-fun-for-anyone