No one questions the importance of effective communication in reporting archaeological findings. Writing is one means of communication, but presenting graphic material (photographs and line drawings) is another. An ambiguous sentence can often distort the truth, and a poorly wrought map or chart can do the same. Relying mainly on maps for his examples, the author points out some common pitfalls in graphic presentation, and develops a generic principle wherein proper differentiation within a graphic is seen as an important means for success.
I became art director of the Journal of Field Archaeology in 1975, the year after it was founded, and have continued in that capacity since. I have been involved in the production of about 70 issues. Because most of the articles have been illustrated, and many of them heavily so, over 5000 pictures have appeared in the JFA. The artwork that has appeared in JFA represents every imaginable style, and the workmanship brought to bear on drafting and creating the charts and maps bespeak every level of skill. JFA does not have a house style for artwork. Unlike the publishers of some periodicals such as Archaeology or Scientific American, we cannot afford to redraw every piece of artwork submitted to us. We occasionally are forced to reject a thoroughly unsuitable, unpublishable illustration, but more often we will make minor improvements, or ask the author to make them.
I decided to review this imposing array of visual material-looking particularly at linear art (maps, charts, line drawings) rather than halftones (illustrations converted from photographs) to see if I could establish what made them good or bad. Like every graphic designer, I developed a set of standards about artwork very early in my career. These included certain obvious criteria, such a uniform line weight, avoiding the use of leroy lettering, keeping the edges of boxes and other geometric shapes neat and tidy, and avoiding the mixing of many different type styles together. Figure 1 has examples that violate some of these criteria to a greater or lesser degree. For the most part I judged artwork intuitively. I knew what I liked, and what I did not like. The time had come to put my intuitions to the test, to see if I could formulate empirical principles that would either confirm my intuitions or alter them.
During the course of re-examining well over 1000 illustrations, I discovered one overriding characteristic nearly always evident in the art I thought was well done and absent in the art I judged to be poor. This quality concerns properly setting off one area (be it physical or cognitive) from another. I formalized this principle as follows: making areas within an illustration distinct, one from another, or whole sets of information distinct, will invariably lead to better graphic presentation. In other words, differentiation is a key to success.
Let us look at some examples of this.
The illustrations in Figure 2 represent a category of art that is usually handled with distinction by archaeologists. All of these examples are drawn from actual objects. Archaeologists take very seriously the task of documenting the fruits of their labor on the printed page. Sherds, arrowheads, statues, stone foundations-no matter what specific form the object takes-once recovered are usually drawn with skill. Sometimes the effects are breathtaking. Stipple drawing seems to be a well-established technique for archaeological artifact drawings, and in terms of its ability to convey detail it has much to offer. Notice in these examples how sharply and clearly the boundaries between areas within the objects are defined. It almost seems that a chisel, not a pen, was used to create them.
In Figure 3, distinctions are made between three sets of information. The artifacts from a shipwreck (anchor, shot, breech chambers, etc.) are made darker than adjoining areas, and a third level of information is provided by means of the light grid marks. Because three sets of information co-exist on three different levels, the task of scanning and absorbing the data is made much easier.
When the subject matter consisted of objects from the real world, I generally found that the objects were drawn precisely and well. But when I looked at the more abstract world of graphs and maps, the level of quality dropped drastically.
A common failing in many illustrations was an over-reliance on, and misuse of, screen tints and patterns. In Figure 4, clear distinctions between one area and the next have been sharply reduced because of the manner in which the patterns have been applied. The visual vibrations brought on by the cross-hatched pattern used in this map create their own share of confusion. What is more, this pattern and two of the others (the three are labeled "Lower terrace," "Upper terrace," and "Lower bajada" in the legend) compete with other details of the map. The mapmaker should have chosen light, less conspicuous patterns, and made them significantly subordinate to those details depicting the overall geography.
Screens and other patterns ought to stand out clearly and distinctly. Too often mapmakers assume that the patterns will stand out properly if each is different, with its own distinguishable style. This is not always enough. One cannot always rely on having the different shapes and characteristics of the patterns, by themselves, tell the story. The mapmaker tried to do this in figure 5A, but with limited success. It is difficult to tell one area from another; one sees an amorphous, gray mass. The map would have been bettered rendered if the patterns chosen had varied more in density, such as was done in Figure 5B, to good effect.
I do not minimize the problems facing the mapmaker or graphmaker when setting off zones and areas. Particularly in archaeological work, the difficulties can at times be formidable and it is not unusual to have 10 or 15 different areas that need to be demarcated. In this situation the artist should not even try to make all the bits and pieces of each area read as a coherent whole. In other words, the fragments of any one subset will have to remain isolated areas; the reader will have to forego making the entire subset intelligible at a glance, and instead decode each area with the help of a key. This approach is successfully demonstrated in Figure 6, which shows a complex set of data about as clearly as we could hope.
A frequent problem with maps is an over-emphasis on contour lines. Unless these are part of the map's central message, they should be subordinated since they tend to drown out other information. The maps in Figure 7, have contour lines that are simply too dominant. Figure 8, in contrast, is an admirable example of how the same kind of information can be kept under control. Here, the contour lines are rendered so lightly and delicately they exist on a separate level, which is where they belong. They leave unencumbered the more important primary data-in this instance the houses and their relationships one to the other.
Type and labeling are important ingredients in graphic material-simply because the amount of lettering in the artwork can be surprisingly great. The percentage of type to linear areas can often approach 30% and sometimes exceeds 50% of the total ink on paper. If one-half of a chart consists of type, and the type is poor, no amount of graceful line work can compensate for the poor labeling and render the artwork useful.
Good typography means selecting the right typeface for the situation, and then handling the type properly. In chart and map work, one should usually avoid leroy lettering. Decent work can be done by means of this system, but to do it well requires considerable experience, and even the best leroy lettering cannot match real type (see FIG. 1).
Another dangerous medium is press-on lettering (a system where letters are rubbed on to paper or acetate). The problem with this form of lettering is that it requires great patience and experience in placing the letters properly, so the base alignment is accurate and letter- and word-spacing are uniform and correct.
Execution accounts for a great deal in successful typography. Even when real type is used, the job will surely be botched if the type is improperly handled. There are four basic ingredients of typography: choice of type; size of type; letter- and word-spacing of type; and the proper placement of the type. These cannot be taught in a journal article any more than one could learn how to excavate an archaeological site that way. But there is one feature of successful typography as it pertains to graphics one can point out here; it concerns type size and placement as it pertains to the central premise of this paper, namely keeping the parts of the whole properly differentiated. Type, like good linework, must obey this same rule.
In Figure 9A, the typography is at fault because it violates the order and clarity that comes from good boundary definition. The type is spread out, becoming a muddle, with each separate label impinging on others. For a label to be effective, it must mind its own business, so to speak. If it overlaps or even mildly threatens areas that are the natural territory of other labels, or if it threatens to impinge upon, or actually bumps into non-type matter-such as geographical features-the eye becomes confused and must spend unnecessary time decoding the information. In Figure 9B I reduced the size of the type from that in 9A, thereby giving each label more breathing room, which in turn allows the reader to decipher more easily which label belongs with which symbol.
Type can often be used to best advantage by establishing boundaries of a different kind: by highlighting different sets of information. Typographical hierarchies are common in maps, particularly where levels of information are dense, and where there are different orders of information. We see it all the time in road maps and atlases. The artist should take advantage of typographic distinctions whenever the situation warrants. In Figure 10, there are four different levels of typographic emphasis, and one has a much easier time understanding the relative importance of each area and is better able to find one's way around.
Nowhere does the issue of good area distinction come up more literally than in distinguishing land masses from water in maps. There seems to be an almost universal disregard for this matter, at least among the maps submitted to JFA. This is a very specific problem that is very easily remedied. What is more, water/land distinction in maps is so utterly basic it can be looked on as symbolic of the whole general matter of area integrity.
If the reader is already familiar with the territory shown in a map, then the ability to differentiate between land and water relies on information that does not have to be present in the map. But confusion arises when the geography is less familiar. As you look at Figure 11 ask yourself whether the lumpy shapes within the map are lakes or islands. The caption, text, and labeling will eventually help the reader sort this out, differentiating water and land, but one should not have to puzzle out such basic information. In Figure 12, stippling helps define the water's edge. In Figure 13, parallel lines create much the same effect, with their suggestion of waves lapping onto the shore.
Sometimes maps and charts can be drawn without any obvious disregard for boundaries, yet still fall short because of a more subtle problem. In Figure 14, the artist has managed to separate one area from the rest. The type is controlled, and does not wander into areas where it does not belong. Screens and other forms of chart material are absent, thus presenting no problem. This map is inoffensive enough, but it suffers from a subtle inadequacy that might be called formlessness. Compare the vague, aimless character of this map with the cohesive structure of Figure 15. Note how the diagonal, heightened line in the latter gives us a point of reference, as does the careful distinction made between the buildings and the contour lines. The formless map presents all its information in one monotonous drone; it has no internal organization. The other, well-formed map has been organized by recognizing the importance of creating distinctions between different kinds of information.
Let me repeat the rule that I mentioned at the outset, and which underlies all the points in this article: making areas within an illustration distinct from one another, or making whole sets of information distinct, will invariably lead to better graphic presentation.
Obviously, other factors contribute to an effective graphic. Typographic finesse is important. Good drafting is clearly essential, with lines carefully drawn and of consistent weight. It helps if the person drawing the graphic has some degree of aesthetic sense, so that proportion and scale are handled intelligently.
Another area of importance is the content and concept of the graphic. No amount of graphic skill can overcome data that mislead, or data that are confused. Such issues are pursued brilliantly and doggedly in Edward R. Tufte's The Visual Display of Quantitative Information (1983), and I urge any creator of maps and charts to study that book. Another useful work for those interested in how best to organize and express numerical data is The Elements of Graphing Data by William S. Cleveland (1985).
I am not a cartographer, mathematician, or statistician, so I must leave these conceptual matters to those trained in those fields. In the course of this study I restricted my judgement to matters of presentation. And when it comes to presentation, the importance of maintaining the integrity of areas within the piece of artwork cannot be emphasized enough. There is nothing terribly profound about this idea and it has its obvious parallels in many other forms of human endeavor, such as graphic design, writing, fine art, and photography. Perhaps what is important about the observation is how consistently it can be applied. I mentioned earlier that I had developed an intuition about good and bad artwork, long before my systematic review of visual material in JFA. I "knew what I liked." In almost every case, my preconceptions were validated by evaluating the art according to the manner in which its internal boundaries were handled. My earlier standards and intuitions needed no revisions.
A useful feature about this theory is that some of its sub-rules can be applied easily to the task at hand. Even while recognizing, of course, that it takes years of practice to become a skilled graphic technician (even in this age of desktop technology), I would offer this "quick-fix" set of rules to those executing graphics.
1. Avoid areas that feature lines or patterns that "vibrate."
2. When using screen tints, keep sufficient contrast between each area to make it distinguishable from the others. Avoid using murky, heavy tones (60-90%) over large areas if at all possible.
3. Render all contour lines lightly, relative to the primary areas of importance. Also, one should subordinate mountains, unless they are part of the primary data.
4. Make water and land masses instantly recognizable as such. In non-color work, two of the best ways to do this are by means of "ripple" lines, drawn parallel to the shore, or by using stippling along the water's edge. Put the lines or stippling in the water, not on land.
5. When positioning typographic labels, be sure to keep each one far enough from any of its neighbors to avoid confusion. This means that type may appear on the printed page as small as seven or eight point (sometimes smaller).
6. If there are different categories of information in a map or chart, use different categories of type. Labels expressed through a typographic hierarchy are usually easier to absorb, particularly if the data set is dense.
There is no easy panacea, no magic list of rules and regulations which, if followed, will automatically lead to the production of good graphic material. But these rules may help the beginner, and act as a refresher and thought-provoker for the professional. They should at least serve as a reminder to everyone that the primary purpose of graphic material-just as with writing-is to convey as much information as the situation warrants, with as much clarity and intelligibility as possible.
David Ford is the art director for the Journal of Field Archaeology, and has been a practicing book designer and graphic designer for 33 years. He worked for 14 years for Harvard University Press, and for the past 18 years has been a free-lance designer. Mailing address: P.O. Box 184, Lincoln, MA 01773-0002.
Bibliography
Cleveland, W. S.
1985
The Elements of Graphing Data. Monterey, CA: Wadsworth
Advanced Books and Software.
Tufte, Edward R.
1983
The Visual Display of Quantitative Information. Cheshire, CT:
Graphics Press.
Figure 1. Some commonly encountered problems in artwork. With one exception, all illustrations in this article are taken from the Journal of Field Archaeology. A) The lettering throughout this illustration was created by a primitive pantographic system known as leroy lettering. The spongy, crude quality, particularly noticeable here, is often a problem. Real type is usually superior, which is quite clear when one compares the leroy lettering in the legend with the same words in real type (shown at the left). B) The lines in this map vary in thickness, to the point where some of them are broken, particularly at the top. The little cross symbols are much too irregular. The stipple dots along the coast are carelessly applied. The lettering was done by hand; real type, being more uniform is often better (compare the hand-lettered "Chora," "Pylos," and "Methone" with these words set in real type, and inserted in parentheses adjacent to the hand-lettered words.
Figure 2. . Examples of six different illustrations that have appeared in JFA over the years. Almost without fail, the drawings received of archaeological objects are well rendered. These are effective drawings in part because the artists have gone to particular pains to set off the various details within each object.
Figure 3. A well designed excavation plan. Careful use of screens in this site map of objects lying on the ocean floor allows the reader to digest the information easily. By using two different screen values, three levels of information are established. By organizing the material hierarchically, the artist has begun the task of unraveling the information on the reader's behalf (Courtesy of Ships of Discovery).
Figure 4. Example of poor pattern selections. Overuse of vibrating patterns always results in confusion. The reader finds it difficult to comprehend the details, and cannot see clearly where one area ends and another begins.
Figure 5. Use of tinting and screening. A) The map has poorly defined areas, because they are too similar in tonality. Even though the area labeled "Wadi Arid" is defined by a screen pattern that is different in composition from the pattern in adjacent areas, the density is about the same. B) The darker screen produces a better contrast with surrounding areas.
Figure 6. Separating different areas clearly. This site plan could have been a visual disaster. Since there are 10 areas being defined, it is very difficult to make each of them visible in its entirety. Through the use of light patterns, the mapmaker very nearly succeeds, and at least makes each area entirely accessible.
Figure 7. Poor use of contour lines. These three maps are all characterized by elevation contours that compete with the primary data, and for all practical purposes overwhelm it. Even if the topographical features are the primary data, the information would be easier on the eye and brain if the lines were lighter and not so overpowering.
Figure 8. Good use of contour lines, showing how to keep them subordinated.
Figure 9. Choice of type size. A) Typographic chaos is created by labels that crowd each other. The labels also get too close to some of the geographic details. B) Reducing the size of the type corrects this difficulty.
Figure 10. Four levels of typography discriminated effectively (Courtesy of the American School of Classical Studies at Athens).
Figure 11. Differentiating land masses and water bodies. Those looking at a map such as this should not have to play detective, assimilating clues from caption, labels, and text to finally discern which areas are water and which land. The distinction should be visually apparent instantly.
Figure 12. Stippling is a good technique for defining the water's edge.
Figure 13. Parallel lines effectively show where land ends and water begins.
Figure 14. This map lacks internal organization and suffers from formlessness. While it is inoffensive and competently executed, the reader is not aware of any ordering of information that aids comprehension.
Figure 15. An example of the effective "layering" of sets of data. The mapmaker has subordinated the contour lines by making them as light as possible. The gray buildings dominate the landscape, as they should. The diagonal, bolder line serves as an organizing, form-giving feature.
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