In direct personal work, such as drawing or painting, when craft conditions other than that of the medium employed are not involved, convention is purely a matter of discretion and consideration of the nature and object of the work; but it is essential in design when the material and method of production have to be considered. In painting the artist may employ the full resources of his palette and be as realistic in his effect as is in his power, but if the purpose be mural decoration restraint is at once imposed. _Undesirable Realism_ Under certain conditions realism would be out of place, and any attempt at illusion would fail to convince. The one time fashion of painting ceilings with sprawling deities of either sex, which cannot be seen without a painful crick in the neck, or worse still to suggest sky with floating amorini, occasionally framed by marble balustrading in wonderful perspective is deplorable. Such decoration, if it can be so termed, is not only stagey but is foredoomed to failure in effect, as the ordinary interior lighting is not adequate. Furthermore, it displays a lack of appreciation of fitness, and that the purpose of a ceiling is to convey a sense of shelter. Realism, though desirable in portraiture, either of individuals, places or events, is not necessarily of the greatest interest except to those concerned. In mural decoration realism should give place to convention, and the whole considered as a design with regard to balance of form and colour, and recognition of the surface to which the decoration is applied. The first attempts at decoration were the direct results of material and the manner of working, in which there was no attempt at representation. This was succeeded when the early artists attained more skill by a phase of realism, later still with acquired culture there was a deliberate return to convention. The dignified conception of the Egyptian rendering of the Lion, though thoroughly conventional, reveals technical skill and anatomical knowledge of a high order; also appreciation for desirable treatment, and may be contrasted favourably with those by Sir Edwin Landseer round the pedestal of the Nelson Column in Trafalgar Square, in which realism is not subordinated to the decorative and symbolic conditions. _Craft Restrictions_ When any craft process is involved the design is only a means to the end, and convention is then imposed by the technical conditions of the craft in question. The designer has to keep these conditions in view, the desirable object being to make the greatest economic use of the process compatible with a good result. It would be a waste of both time and energy to depict effects that could not be realised.