From the standpoint of dollars and cents, this chapter contains the most important information in the book. A project in plastics can be designed economically, or it can be designed wastefully, so that the material costs two or three times what it should, with no improvement in the effect produced.
The essential principles of economical designing in plastics are not difficult to grasp. Structurally speaking, cast resins are an expensive material, when compared with wood, sheet metal or other materials they are supplanting, but ornamently speaking, they are the cheapest, from the standpoint of the amount of beauty and eye-appeal provided per dollar of cost. The main point in economical design, therefore, is to use plastics for ornamental purposes, and not for structural purposes — in other words, do not waste material in places or thicknesses which cannot be seen. Use wood, metal or "air" in places where structural strength are necessary or where mere "bulk" is desired, and use thinner sections of plastics where ornamentation is desired.
A glance at a typical group of commercial products and a typical group of amateur-designed products will clearly illustrate this point. The amateur will use a piece of No. 3 cylinder in a place where the professional would use a No. 6, one-third as thick. The amateur would use a solid 1" block for the base of a project, where the professional would make the base of wood, or a box of 1/8" sheet. The professional would use a thin ring-tube, where the amateur would carve his ring out of a solid chunk or rod, throwing away the material drilled out of a solid sheet, wasting the material sawed out, and so on. Of course, the amateur is usually making only one of a thing at a time, and is working in plastics for pleasure or education whereas the professional is in it for bread and butter, but a little attention to the economics of the situation will save many dollars worth of material, produce designs in better taste, and leave material over for additional projects that otherwise would be swept up as scrap. In group or school work particularly, this can quickly become an expensive practise.
Plastics are sold by the pound, therefore the cost of the raw material is determined entirely by its weight. The entire struggle in commercial design is to reduce the weight, by every possible means. Using thinner saw-blades, for instance, saves money. "Slicing" as contrasted with sawing, as another instance, wastes no material at all in saw-dust, and is therefore preferred. These instances are mentioned merely to show the close attention to economies in design and methods of manufacture, all aimed at the end of keeping down the weight, to produce the greatest possible effect with the least material. To the amateur craftsman or student, this may seem unimportant, but it is the life of the business.
A good example as to an expensive and an economical design is given in the two clock-designs in previous Chapters, Projects Nos. 30 and 9. The former is a box-shaped clock built entirely of plastic sheet and rod. It is a rich-looking, as well as an economical design, for the main bulk of the clock is "air" —meaning that the clock is a hollow box, formed of thin sheet, yet it gives the appearance of a heavy block shiny jet. It is a good design in its way, yet it weighs twice as much, and is only half as large and bulky-appearing as the clock in Project No. 9. In other words, the effect produced costs four times as much as the effect produced in the second design, which is every bit as beautiful. The latter design consist only of four narrow strips of jade material, bent to form the bands around the clock, the small pieces of sheet for the top and face. The "bulk" in this case is supplied by the wooden block which forms the body of the clock. This maple, natural finish, which is in keeping with the modern design of the clock, yet an unobtrusive color which makes the brilliant jade trimmings "stand out". In combining colors and materials therefore, bear in mind that the eye is automatically drawn to the brightest color, which becomes the feature of the design, and that even though it occupies only a very minor position structurally and may be very small in bulk as compared with the balance of the project, it is the biggest thing in sight to the average eye. As you raise the tone of your colors and polish, you can automatically lower your bulk, without disturbing the general eye-value balance.
The carved jade lamp, Project No. 28 is another example of the use of "air" in a design. (The term "air", it might be said in passing, is a common one around the commercial designing shops— "It weighs too much, put more 'air' into it"). The eye tends to fill in blank spaces if they are surrounded by brilliant colors. The same weight of material as is contained in the little section of bracelet-cylinder forming the upright portion of this little lamp, if compressed into a round rod, would appear to be a spindly, trifling thing, but when it is "spread out" as it is in this design, it produces the illusion of bulk.
Another example of the contrast between amateur methods and professionals is given in Project No. 35, the chess set, where both styles of manufacture are described. Note that in the professional design, the weight of material required is only about half. Still another example might be a carved round dress-clip, say 1 1/4" in diameter. This could be made of a section cut off of a 1 1/4" round rod, 3/4" thick, and carved from the center down, rounding down the edges. No doubt it would be very beautiful, but it would likewise be a very wasteful design, and a much less expensive, but much more eye-catching design would be to use a section only 1/4" thick—one-third the material—and cement in the center of it a small piece of 1/2" rod of a strongly contrasting color, and carve the whole down as one piece, or cut the second piece in such a way as to require no machining, merely serving as a color-spot, see Figure 65. Additional comparisons of economic and uneconomic designs could" be given, but the sum and substance of the correct principle of design of plastics articles may be summed up in a few words—"a little bit of plastics goes a long way when properly used and the colors properly chosen."
Fig. 65. Showing the contrast in expense for material between a button turned from solid 94" material above, and made ap from 1/4" material below with cemented ornament.
Difficulties in Supplying Homecraft Trade
It might be well to bring out this point that the companies manufacturing cast resin plastics have no bed of roses in dealing with the homecraft trade, and in justice to these companies, the reasons for this situation should be explained. Homecraft business is so difficult for them to handle, in fact, that were it not for tie efforts of the writer and others of a small group who have become sort of "liason officers" between homecraftsmen and the manufacturers, cast resins would not even yet be available for amateur use, despite the fact they have been available to industry for seven or eight years.
The reason for this is that it is more or less a "custom-made" business—certain specified shapes and colors are poured only on orders for that particular shape and color from fabricators. A complete stock of only ONE piece in every size and color would require 150,000 or 200,000 different pieces on the shelves, and even that, as stated, would only provide one sample of each kind, in each color. There are around 300 different colors, and probably well over 2000 shapes. When a fabricator has an order for so many thousand gross of rings, bracelets, clocks or what-not, he places an order for the number of pieces of the shape and color specified, amounting to a ton or more of material as a rule, the plastics company makes up and pours one or more kettles-full of this color, and delivers the shipment in ten days or so. If there was any raw material left over in this particular kettlefull, it is run into the same or other standard molds and this "overage" put into stock on the shelves. But when a homecraftsman sends in an order, it is for one of this and one of that, and possibly two of something else—every piece a different shape and color, and weighing a half-pound or more each. The manufacturing companies simply are not "geared up" for this type of business—the smallest amount of any one color they can run is a kettle-full, or on rare occasions a half-kettle, which is 375 pounds, and the smallest number of pieces of the same kind and color they can pour at one time is from 9 to 40 pieces, depending on the size, or a complete mold. Even if "Morrocco Red" for example, is being run that day on a big order, they cannot run a mold-full of 40 ring-shapes merely to fill an order for one piece, and put the other 39 ring-shapes on the shelf. Moreover, many colors are "seasonal", and are only run in the Spring, or in the Fall, while others are "special", and only made up on special order. From this brief explanation of the modus operandi of a plastics plant therefore it can easily be seen that, however much the plastics companies may want to accommodate small customers, it is an exceedingly difficult problem to work out, although some progress has been made. Plastics are a far cry from lumber, metal and other crafts materials, which come in only one color and a limited number of shapes, and where it is as easy to fill an order for one piece as a thousand, and in justice to the plastics companies, it is well that this problem should be understood.
The companies themselves are as anxious as the craftsman are to make the material available to them—they realize that every craftsman becoming familiar with the material will take an interest in commercial products which use it, and buy them in preference to other merchandise not using plastics. They realize also that a certain percentage of the students and experimenters thus becoming acquainted with this material will some day become industrial buyers of it, or have some influence on industrial buying, whether it be a year from now or ten years hence. They are therefore extremely anxious to cultivate the growing homecraft and school interest in plastics, and are willing to cooperate in every possible way, even to the extent of handling business that is unprofitable, if a way can be found to minimize their difficulties, and it is the purpose of this chapter to aid in this campaign to the end that plastics will become easier and cheaper to buy.