By Mel Gooding
By Andy Goldsworthy
By Virginia.Chieffo Raguin
By David Hopkins (Professor of Art History, University of Glasgow)
By Alex Michaelides
By Dale Chihuly
By Justin Carville
By Hossein Amirsadeghi, Maryam Eisler
By Elena Crippa
By Paul Bonaventura
By Catherine Bernard-Gruber, Armelle Vanazzi
By Veronica Gould
By Anne Lyles, Sarah Cove, John Gage, Charles Rhyne, Franklin Kelly
By Eric Broug
By Kim W. Woods
By Heidi Zojer, John Klapper, Ruth Whittle (University of Birmingham, UK), William J Dodd (University of Manchester, Christine Eckhard-Black (University of Oxford
By Paul Cezanne, Richard Kendall
By Marjorie Caygill
By Elinor Gadon
By Vincent Boele
By Jesse McDonald
By James Beck
By Judith Wechsler
By John House
By Deborah Gribbon, J. Paul Getty Museum
By William Gaunt
By N.E.Thing Enterprises
By Judith Collins, etc.