Vary the contours to be sympathetically related to these design motives, provided such variation of the original primary ma.s.s is necessary to complete unity.

(_j_) Add additional views, dimension, and otherwise prepare the drawing for shop use.

SUGGESTED PROBLEM

Design a copper nut bowl and spoon. Enrich with a chased border appropriate to the subject. Enrich spoon, using fitting method of enrichment. The bowl and spoon should have a harmonious relation.

SUMMARY OF RULES

SURFACE ENRICHMENT OF LARGE PRIMARY Ma.s.sES

Rule 11a. _The preliminary steps toward surface enrichment should be thought out before they are drawn._

Rule 11b. _Conservative application should mark the use of surface enrichment of large ma.s.ses. Its use should: (1) lighten or soften necessarily heavy construction; (2) support or apparently strengthen good structure; (3) add interest to large unbroken and uninteresting surfaces._

Rule 11c. _The type of design unit for large ma.s.ses should be bolder than similar designs for small primary ma.s.ses._

Rule 11d. _The eye should be attracted to one princ.i.p.al zone of enrichment, whether located upon the primary ma.s.s, appendage, terminal, links, or details. All other zones should be subordinate to this area._

Rule 11e. _Two periods of historic ornament should not be introduced into the same design._

Rule 11f. _Repulsive forms should not be introduced into surface enrichment._

REVIEW QUESTIONS

1. Contrast the method of enriching large and small areas of base and precious metals. Ill.u.s.trate. What is the character of surface enrichment for large areas?

2. Name three essentials to good surface design for base and precious metals. Ill.u.s.trate each.

3. Give nine steps necessary for the complete evolution of surface enrichment.

4. Name method of cla.s.sifying the structural forms of metal into four groups. How does this compare with the cla.s.sification of clay forms?

5. Between which two groups does the transition from a horizontal to a vertical primary ma.s.s occur?

6. Is there a perceptible change in the surface enrichment paralleling this change in proportions of the primary ma.s.s?

7. In which group or groups is the relation between surface and contour enrichment closest?

8. Give the characteristics of surface enrichment designed for flat or semi-flat planes.

9. State the value of the terminal as an enrichment zone.

10. Discuss common errors in the surface enrichment of hardware and their correction.

11. In what manner does historic ornament influence industrial design? Why?

12. Give characteristics of surface enrichment designed for, (_a_) large, shallow circular forms; (_b_) large, low cylindrical forms; (_c_) large, high cylindrical forms.

13. How does the point from which the article is to be seen affect the character of the design?

CHAPTER XV

COLOR: HUE, VALUE, AND CHROMA; STAINS

[Sidenote: Need of Harmonious Color]

In the previous chapters we have developed problems dealing with proportions, contours, and surface enrichment. The use of color, particularly in surface enrichment, is equally important inasmuch as its use is often necessary to bring the project, as for example a piece of furniture, into harmony with the surroundings which furnish its final color environment. The incorrect use of color may seriously mar a project otherwise correctly designed in line and form, and may also weaken its influence in a particular setting.

[Sidenote: Use of Color Systems]

While there are a number of excellent systems of color notation, it is well to bear in mind that a color system, however excellent, is a good servant but a poor master. It is nevertheless considered as essential to have a definite knowledge of some systematically developed color system in order that we may methodically apply color to the structural form with some degree of certainty.

[Sidenote: Color Pigments for Design Rendering]

For rendering drawings of problems involving the use of color it is suggested that the beginner use the tempera, or opaque colors now on the market. These colors readily adapt themselves to the average problem, while their rich hues are more successful than those produced from the ordinary water colors. Tubes of cobalt blue, ultramarine, light chrome yellow, vermilion, emerald green, crimson madder, black, and white will serve to solve the problems demanded by this chapter.

[Sidenote: Application of Pigment]

White is used to lighten and black to darken the pigments, which should be mixed with water to the consistency of cream, and applied to cover well the surface of the paper. One should guard against a thin, transparent wash, as the desired effect is a velvety opaque and evenly tinted surface only possible with the thick application of color. The pigment will dry out about one-quarter lighter than when first applied.

The usual school color box of three pigments is useful for rendering wood stains. These pigments may be used in thin flat washes and will exhibit a transparent effect a.n.a.logous to the effect of a wood stain.

The natural color of wood may be first represented and, when dry, followed by a second thin wash of the hue of the wood stain.

[Sidenote: Rendering of Wood Stains]

Lacking as we are in a definite color nomenclature or standards, it now becomes necessary to describe the processes and define the terms necessary to the designer.

[Sidenote: Hue and Hue Rectangles]

_Hue_ is the technical name for color; a change of color means a change of hue. For the designer's purposes we will select twelve equally graded colors or hues from the spectrum and term them standard hues. Each hue will have twenty-seven modifications or gradations, which is a sufficient number for our purpose. These gradations are to be graphically recorded by and contained in a diagram to be known as a _hue rectangle_. There are twelve of these rectangles, one for each of the selected hues, and they are found arranged in sequence in Figure 454.

[Sidenote: Standard Hues]

[Sidenote: Full Chromatic Intensity]

By referring to Figure 455, it is seen that the twelve selected standard hues are represented at what is termed _full chromatic intensity_, which, to the designer, means hues of the full strength of his color pigment. This is far short of the true color intensity of the spectrum, but for industrial arts purposes these hues are strong enough to serve as standards for comparison and cla.s.sification. The hues should be evenly graded from red at the left to red violet at the right without noticeable unevenness in the gradations. Red violet is the link which connects the right end with the left, thus completing the circuit of the twelve hues. The following pigment table gives name and symbol of various hues.

[Sidenote: Approximate Related Standard Hues]

--------------+-----------------------------------+------------+------- HUES | PIGMENTS | VALUES |SYMBOLS --------------+-----------------------------------+------------+------- Red | Pure crimson madder | High dark | R-HD Orange | Crimson madder and vermilion | Middle | OR-M Orange | Vermilion and light chrome yellow | Low light | O-LL Orange yellow | Vermilion and light chrome yellow | Light | OY-L Yellow | Pure light chrome yellow | High light | Y-HL Yellow green | Light chrome yellow and | | | emerald green | Light | YG-L Green | Pure emerald green | Low light | G-LL Green blue | Emerald green and cobalt blue | Middle | GB-M Blue | Pure cobalt blue | High dark | B-HD Blue violet | Ultramarine and crimson madder | Dark | BV-D Violet | Ultramarine and crimson madder | Low dark | V-LD Red violet | Ultramarine and crimson madder | Dark | RV-D --------------+-----------------------------------+------------+-------

[Sidenote: Locating Standard Hues]

It now becomes imperative to locate each standard hue at its definite place in each rectangle. This invariably occurs at a predetermined point in the left vertical boundary of the rectangle of that hue. From inspection of Figure 455, it is quickly seen that violet seems to be the darkest hue; yellow the lightest, with the others between these hues.

This variation of what is termed their value gives us a guide to their proper placing in the hue rectangle.