Rule 4c. _The appendage should, if possible, echo or repeat some lines similar in character and direction to those of the primary ma.s.s._

OUTLINE OR CONTOUR ENRICHMENT

Rule 5a. _Outline enrichment should be subordinated to and support the structure._

Rule 5b. _Outline enrichment should add grace, lightness, and variety to the design._

Rule 5c. _Outline enrichment, by its similarity, should give a sense of oneness or unity to the design, binding divergent members together._

Rule 5d. _Parts of one design differing in function should differ in appearance but be co-ordinated with the entire design._

Rule 5e. _In cylindrical forms outline curves with a vertical tendency should have their turning points or units of measurement in accordance with the horizontal divisions of Rules 2a and 2b._

Rule 5f. _Dependent outline enrichment should be related to essential parts of a design and influenced by their forms and functions; it must be consistent with the idea of the subject._

Rule 5g. _A curve should join a straight line with either a tangential or right angle junction._

SURFACE ENRICHMENT

Postulate. _The design should conform to the limitations and requirements of tools, processes, and materials, and should be durable and suitable for service._

Rule 6a. _Surfaces to be enriched must admit of enrichment._

Rule 6b. _Surface enrichment must be related to the structural contours but must not obscure the actual structure._

Rule 6c. _The treatment must be appropriate to the material._

CONTINUOUS BANDS AND BORDERS FOR PARTLY ENRICHED SURFACES

Rule 6d. _Bands and borders should have a consistent lateral, that is, onward movement._

Rule 6e. _Bands and borders should never have a prominent contrary motion, opposed to the main forward movement._

Rule 6f. _All component parts of a border should move in unison with the main movement of the border._

Rule 6g. _Each component part of a border should be strongly dynamic and, if possible, partake of the main movements of the border._

Rule 6h. _Borders intended for vertical surfaces may have a strongly upward movement in addition to the lateral movement, provided the lateral movement dominates._

Rule 6i. _Inlayed enrichment should never form strong or glaring contrasts with the parent surface._

Rule 6j. _Carved surface enrichment should have the appearance of belonging to the parent ma.s.s._

ENCLOSED ENRICHMENT--PARTLY ENRICHED PANELS FOR SURFACE ENRICHMENT

Rule 7a. _Marginal panel enrichment should parallel or be related to the outlines of the primary ma.s.s and to the panel it is to enrich._

Rule 7b. _Marginal points of concentration in panels should be placed (1) preferably at the corners or (2) in the center of each margin._

Rule 7c. _To insure unity of design in panels, the elements composing the point of concentration and links connecting them must be related to the panel contour and to each other._

ENCLOSED ENRICHMENT--FULLY ENRICHED PANELS FOR SURFACE ENRICHMENT

Rule 7d. _The contours of fully enriched panels should parallel the outlines of the primary ma.s.s and repeat its proportions._

Rule 7e. _The points of concentration for a fully enriched square panel may be in its center or in its outer margin._

Rule 7f. _The points of concentration for a fully enriched vertical panel should be in the upper portion of the panel._

Rule 7g. _The fully enriched panel and its contents should be designed in unified relation to the structural outlines, with the center line of the panel coinciding with the inceptive axis of the structure._

FREE ORNAMENT FOR PARTLY ENRICHED SURFACES

Rule 8a. _Free ornament for partly or fully enriched surfaces should be based and centered upon an inceptive axis of the structure._

Rule 8b. _Free ornament should be related and subordinated to the structural surfaces._

Rule 8c. _Points of concentration in free enrichment of vertically placed ma.s.ses are usually located in and around the inceptive axis and above or below the geometric center of the design._

SURFACE ENRICHMENT OF CLAY

Rule 9a. _Surface enrichment of clay must be so designed as to be able to withstand the action of heat to which all ware must be submitted._

Rule 9b. _Incised, pierced, and modeled decoration in clay should be simple and bold and thus adapted to the character of the material._

Rule 9c. _A border should not be located at the point of greatest curvature in the contour of a cylindrical form. The contour curve is of sufficient interest in itself at that point._

SURFACE ENRICHMENT OF BASE AND PRECIOUS METALS FOR SMALL Ma.s.sES

Rule 10a. _Designs in precious metals should call for the minimum amount of metal necessary to express the idea of the designer for two reasons: (1) good taste; (2) economy of material._

Rule 10b. _Contour and surface enrichment should never appear to compete for attention in the same design._

Rule 10c. _Parts of a design differing in function should differ in appearance but be co-ordinated with the entire design._

Rule 10d. _Surface enrichment should at some point parallel the contours of both primary ma.s.s and point of concentration especially whenever the latter is a stone or enamel._

Rule 10e. _In the presence of either stone or enamel as a point of concentration, surface enrichment should be regarded as an un.o.btrusive setting, or background._

Rule 10f. _Stone or enamel used as a point of concentration should form contrast with the metal, either in color, brilliancy, or value, or all three combined._