A process for printing on to a 3-dimensional article is described. An image is printed on to a first side of a stretchable carrier membrane having a first side and a second side. The membrane is mounted in a plane within a frame between a heating chamber defined on one side of the membrane, and an article receiving chamber defined on the other side of the membrane. A 3-dimensional article to be printed is placed on to a generally flat platen positioned generally parallel to the said plane, optionally with a nest for the article thereon, within the article receiving chamber. A thermo- and vacuum-forming step is performed in which there is relative movement of the platen with respect to the membrane in a direction perpendicularly to the said plane to bring the article into register with the image printed on the membrane and to carry the article into intimate contact with the membrane through the said plane into the heating chamber. A source of vacuum is applied to the membrane from the said other side, and heat is applied to the membrane from the said one side at a first temperature sufficient to soften the membrane, whereby the membrane is thermo- and vacuum-wrapped at least partially about the article with the membrane in intimate contact with surface details of the article. A dye-diffusion step is performed in which infra-red radiation is applied to the article with the membrane wrapped therearound using at least two infra-red sources to heat the membrane and underlying surface of the article over substantially a half-spherical solid angle uniformly to a temperature in excess of the first temperature and for a time sufficient to cause the printed image to diffuse into the surface of the article but insufficient to damage the article.