Diamond painting is a tasteful cross between paint by numbers and mosaic art with a cross-stitch finish. It is a unique art form where you paste diamonds on to a canvas, that has a certain design of your choice, to create a magnificent painting. What Makes Diamond Painting So Special?... Diamond painting is a tasteful cross between paint by numbers and mosaic art with a cross-stitch finish. It is a unique art form where you paste diamonds on to a canvas, that has a certain design of your choice, to create a magnificent painting. What Makes Diamond Painting So Special?...