What applies to the form of pottery applies equally to its decoration; often it is impossible to disassociate them. The actual or primitive technique of manufacture, too, may exhibit itself in and as an ornament, as, for example, the spiral markings in pottery made in the coil method. We have seen that in some places plaited or woven fabrics have been used to support the soft clay, and these have left their impress. If not previously destroyed, these marks become indelible after the burning of the pottery. These markings being due to the process of manufacture, are repeated in the manufacture of every vessel, and if not purposely smoothed out, expectancy comes into operation, and they may be imitated in a slightly conventional manner even when they may no longer occur in construction, as, for example, when the supports are no longer employed, or in pottery turned on a wheel.
Various methods of plaiting, intertwining, netting, and so forth may thus be transferred as skeuomorphic decoration to pottery. These are at first produced by means of incisions, puckerings of the clay by the fingers, application of accessory coils or pieces of clay, etc. Even the accidental imprints of nails or finger-tips, or of implements, may have suggested certain decoration.
Later on, when pottery was decorated by painting, the same kind of ornamentation was reproduced in the new medium, and as the changed conditions evoked freer treatment, the designs underwent various transformations.
Mr. Holmes[45] discusses the modification of ornament (1) through material, (2) through form, (3) through methods of realisation (p. 458).
(1.) The material of which an object is made must have a very definite effect upon its decoration, and the material is to a very large extent dependent upon the locality. Metal, stone, clay, wood, bone, skins, and textiles are so varied in their structure that they require different artistic treatment, and it has usually taken a considerable time for a people to discover what is the most suitable form of decoration for an object made of a particular substance.
(2.) The forms of decorated objects exercise a strong influence upon the decorative designs employed. An ornament, as Mr. Holmes remarks, applied originally to a vessel of a given form, accommodates itself to that form pretty much as a costume becomes adjusted to the individual. When it came to be required for another form of vessel, very decided changes might be necessary.
Figs. 56 and 57.—Variations in a motive through the influence of form. Pueblo pottery; after Holmes.
The ancient Pueblo peoples were very fond of rectilinear forms of meander patterns, and many earthen vessels are found girdled with a beautiful angular pattern. (Fig. [56].) When, however, the artist has to decorate a vessel which has rounded prominences in its central zone, he finds it very difficult to apply his favourite device, and he is practically compelled to convert his angled into a spiral meander. (Fig. [57].)