Industrial Arts Design Part 24

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._

[Sidenote: Evolution and Technical Rendering of Processes]

A non-technical and brief description of each process follows. All designs in this chapter may be identified by referring to the process numbers after the figure description as 1, 3, 5; 2, 4, 6, corresponding to the key numbers on Plate 52. A design to be submitted to the craftsman should be a graphic _record of technical facts_ in addition to good design, which requires that we should have an expressive _technical means of rendering each process_. The last column, on Plate 52, indicates this rendering. In addition to this rendering each one of the eight technical processes has been carried through three design steps.

1. (first column, Plate 52) Planning the original primary ma.s.s, with its inceptive axis suggested by the structure and intended use. It pa.s.ses through the point of concentration. 2. (second column, Plate 52). The division of the primary ma.s.s into zones of service and enrichment with the suggestion of the leading lines which, at some points, are parallel to the contours and lead up to the point of concentration. The contours in this column have, in several instances, been changed to add lightness and variety to the problem. 3. The last step (column three, Plate 52) shows the design with graphic rendering suggestive of the completed process.

[Ill.u.s.tration: SURFACE ENRICHMENT OF SMALL PRIMARY Ma.s.sES IN METAL WITH EVOLUTION AND RENDERING OF EIGHT PROCESSES OF ENRICHMENT

PLATE 52]

TECHNICAL PROCESSES AND METHODS OF ILl.u.s.tRATING SAME IN A DESIGN

[Sidenote: Piercing]

1. Removal of design unit or background by means of the jeweler's saw.

Bridges of metal should be left to support firmly all portions of the design. Test this by careful study of the design. Rendering--shade all pierced portions of the design in solid black. Slightly tint portions of the design pa.s.sing under other parts. Ill.u.s.tration, Figure 336.

Rule 10j. _All surface enrichment should have an appearance of compactness or unity. Pierced spots or areas should be so used as to avoid the appearance of having been scattered on the surface without thought to their coherence._

[Sidenote: Etching]

2. Coating either design or background with an acid resistant, to be followed by immersion of the article in an acid bath. Allow the unprotected portion to be attacked and eaten by the acid to a slight depth. Rendering--slightly tint all depressed or etched parts of the design. Ill.u.s.tration, Figure 339.

[Sidenote: Chasing or Repousseing]

3. The embossing and fine embellishment of a metal surface by the application of the hammer and punches. The work is conducted mainly from the top surface. Rendering--stipple all parts of the background not raised by the process. Chasing should seem an integral part of the background and not appear stuck upon it. Ill.u.s.tration, Figure 342. Rule 10k.

[Sidenote: Enameling (Champleve)]

4. A process of enameling over metal in which the ground is cut away into a series of shallow troughs into which the enamel is melted.

Exercise reserve in the use of enamel. Over-decoration tends to cheapen this valuable form of decoration. Rendering--shade the lower and right-hand sides of all enameled areas to suggest relief. Ill.u.s.tration, Figure 345. If possible render in tempera color.

[Ill.u.s.tration: SURFACE ENRICHMENT OF SMALL PRIMARY Ma.s.sES IN PRECIOUS METAL

CONTOUR AND SURFACE ENRICHMENT OF FLAT PLANES PINS AND BROOCHES

PLATE 53]

Rule 10i. _Caution should be exercised with regard to the use of enamel.

Over-decoration by this material tends to cheapen both process and design._

Rule 10l. _The lanes or margins between enameled spots should be narrower than the lane or margin between the enamel and the contour of the primary ma.s.s._

[Sidenote: Inlaying]

5. The process of applying wire, etc., to an incision on metal either by burnis.h.i.+ng or fusing the metal into the cavities. Rendering--tint the darker metal or, if possible, render in color. Ill.u.s.tration, Figure 348.

[Sidenote: Stone Cutting]

6. An enrichment of the surface by the addition of semi-precious or precious stones. Other enrichment is generally subordinated to the stone which then becomes the point of concentration. All enrichment should lead toward the stone. Small stones may, however, be used to accentuate other points of concentration in surface enrichment. Rendering--shade the lower and right-side of the stone to suggest relief. Pierced subordinate enrichment should be shaded in solid black. A concentric line should be drawn outside of the contour of the stone to designate the thin holding band, or bezel, enclosing the stone on all sides.

Ill.u.s.tration, Figure 351.

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._

[Sidenote: Building]

7. The process of applying leaves, wire, grains, and other forms of surface enrichment to the plane of the metal. These may afterwards be carved or chased. Rendering--shade the lower and right-hand lines; slightly tint the lower planes of the metal. Ill.u.s.tration, Figure 354.

[Ill.u.s.tration: _Courtesy of the Elverhoj Colony_

Figure 372a.--Tie Pins]

8. The process of depressing or raising certain portions of the metal surface by means of chisels and gravers. By the use of these tools the surface is modeled into planes of light and shade, to which interest is added if the unaggressive tool marks are permitted to remain on the surface. Rendering--shade the raised and depressed portions to express the modeling planes. As this is a difficult technical process the designer is advised to model the design in plastelene or jewelers' wax first. Ill.u.s.tration, Figure 357.

[Ill.u.s.tration: _Courtesy of the Elverhoj Colony_

FIGURE 372b.--Tie Pins]

[Sidenote: Carving]

Rule 10k. _Built, carved, and chased enrichment should have the higher planes near the point of concentration. It is well to have the stone as the highest point above the primary ma.s.s. When using this form of enrichment, the stone should never appear to rise abruptly from the primary ma.s.s, but should be approached by a series of rising planes._

[Sidenote: Planis.h.i.+ng]

9. The process of smoothing and, at the same time, hardening the surface of the metal with a steel planis.h.i.+ng hammer. The hammer strokes give an interesting texture to the surface which may be varied, from the heavily indented to the smooth surface, at the will of the craftsman. The more obvious hammer strokes are not to be desired as they bring a tool process into too much prominence for good taste. Rendering--print desired finish on the drawing.

[Sidenote: Frosting]

10. A process of sand blasting or scratch brus.h.i.+ng a metal surface to produce an opaque or "satin" finish. Rendering--similar to planis.h.i.+ng.

[Sidenote: Oxidizing]

11. A process of darkening the surface of metal by the application of chemicals. Pota.s.sium sulphite will supply a deep, rich black to silver and copper. Rendering--see Planis.h.i.+ng.

[Sidenote: Design of Pins and Brooches]

The eleven processes mentioned above are among those which, by recent common practice, have become familiar to the craftsman in precious metals. While they do not cover the entire field, they at least give the beginner an opportunity to design intelligently in terms of the material.

[Sidenote: Dependent Surface Enrichment for Pins]

Plate 53 is mainly the enrichment of the flat plane by the addition of semi-precious stones (process six). Whatever surface enrichment is added to this design becomes _dependent_ enrichment and quite a.n.a.logous to _dependent_ contour enrichment, Plate 29, inasmuch as it has to be designed with special reference to the shape and character of the stone.

Figures 358 to 363 are examples of _dependent contour_ enrichment; Figures 364 to 371 are examples of _dependent surface_ enrichment.

Figures 358 to 367 are based upon _vertical_ inceptive axes as appropriate to their intended service. The point of concentration may be located at practically any point on this inceptive axis, provided the major axis of the stone coincides with the inceptive axis. The best results are obtained by placing the stone a little above or below the exact geometrical center of the primary ma.s.s.