As the design is to be limited to the margin, the panel outline is bound to parallel the contours, or outlines, of the surface to be enriched. It is well to begin the design by creating a panel parallel to the outlines of the enriched surface. [Figure 218]. The next step is to place the point of concentration in the marginal zone and within this figure. Common usage dictates the corners as the proper points. It may be the designer's practice to use the single or double bands, [Figures 218], [219], [220], with a single accentuation at the corners. The spots composing the point of concentration must have unity with the enclosing contours and with the remainder of the enrichment. [Figure 220] is, in this respect, an improvement over [Figure 219]. But these examples are not true enclosed panel enrichment. They are the borders of [Chapter IX] acting as marginal enrichment. It is not until we reach [Figure 221] that the true enclosed enrichment appears, when the panel motive is clearly evident. In this figure a single incised band parallels the contours of the figure until the corner is reached. Here we find it turning, gracefully widening to give variety, and supporting the structure by its own increased strength. The single band in [Figure 221] acts as a bridge, leads the eye from one point of concentration to the next similar point, forms a compact mass with the point of concentration, and parallels the enclosing contours of the enriched surface.
Points of Concentration in the Center of Margin
In [Figure 222] the point of concentration is to be found in the center of each margin. This bilateral unit is clearly designed on and about the center lines of the square panel. These points of concentration take the place of previous concentrations at the corners which were based upon the square's diagonals. While accenting based upon the center lines is acceptable, this means of concentration does not seem so successfully to relate the accented part to the structural outlines as that of concentration based upon the diagonals. The latter, therefore, is recommended for beginners. The corners of [Figure 222] are, however, slightly accented by means of the bridging spots x-x.
Inceptive Axes or Balancing Lines
The diagonals and center lines of the surface enriched squares of [Figures 221] and [222] and similar structural lines are inceptive axes, as they are center lines for new design groups. It may then be said that a strong basic axis or similar line depending upon the structure, may become the center line or inceptive axis upon which to construct a bilateral design. It is only necessary to have this inceptive axis pass through the enrichment zone of the panel. Hereafter in the drawings, inceptive axes will be designated by the abbreviation I.A. while the point of concentration will be indicated by the abbreviation P.C.
Plate 36
Inceptive Axis