Guidelines for Making
Tactile Diagrams and Accompanying Narratives
What Is a Tactile Diagram?
Essentially, tactile diagrams are maps used in conjunction with detailed verbal narratives. Tactile diagrams are not exact relief reproductions of visual images. Rather, they are translations of visual images into a tactile language. Tactile diagrams are always used in conjunction with verbal narratives that guide the user through the diagram in a logical and orderly manner. Additionally, the narrative provides art-historical information and a detailed description of the actual work. Tactile diagrams will not work without accompanying verbal narratives. To create a tactile diagram, you must follow a series of steps.
There are basically three categories of images: 1) a simple image; 2) a complex image that must be broken down into multiple diagrams; and 3) a highly complicated image that cannot be translated into a tactile diagram. Both simple and complex images can be translated into tactile diagrams. However, if an image is too complicated, it might not be possible to translate it into a tactile diagram. An image is considered too complicated when it includes too many objects or small details. Here are some examples of different kinds of images:
Cave paintings lend themselves very well to tactile diagrams because they are simple drawings with simple lines.
This is a tactile translation of the Chinese Horse from the Lascaux Cave Paintings in France.
A Complex Image Broken Down into Multiple Diagrams
To illustrate this example, we use The Gathering of the Manna, by Peter Paul Rubens.
Due to the complexity of this image, it was broken down into three diagrams. The first diagram illustrates the background. The second illustrates only the objects, minus the background and foreground. The third and final diagram ties everything together in a composite diagram that comprises the background, the objects, and the foreground. The user puts together the diagrams like the pieces of a puzzle, or builds the image layer by layer.
An Image Too Complex to Be Translated into a Tactile Diagram
It would be impossible to translate this image of Claude Monet’s Japanese Bridge over the Lilac Pond at Giverny into a tactile diagram because the edges are very fuzzy—there are no clearly defined shapes. It would also be impossible to illustrate the role of color and the optical effects created by the juxtapositions of shades.
Keep in mind that some complex images will require more than one diagram. They must be broken down into a sequence of diagrams. However, you should use no more than three or four diagrams to illustrate an image. If you use more than four diagrams, the user will not be able to synthesize the information into a cohesive mental image. Instructions for separating the image into multiple diagrams are included later in this discussion.
Each work of art deserves individual consideration. No two images will be translated in the exact same way because each work presents its own challenges. There are, however, problems that are common to most images. Accordingly, these instructions comprise a general set of guidelines or rules that can be applied to almost any image.
Creating Tactile Diagrams
First, examine the image selected for translation and determine its significance. It is important to have some knowledge of the work of art. You must decide what visual information you need to convey in the diagram in order to illustrate the most important aspects of the work. The diagram should include only the information that will be discussed in the verbal narrative. All other details must be omitted. Details that are depicted in the diagram but not explained in the verbal description will cause confusion.
You must also be aware of the kinds of information that can be conveyed in a tactile diagram. Basic shapes and schematic renderings of a composition or object are translatable. Other kinds of information must be conveyed in the verbal narrative. For example, it is not possible to illustrate modeling—the use of light and shade to represent the three-dimensionality of forms—in a tactile diagram. Modeling can be described only in the verbal narrative. In general, visual illusions, such as certain types of perspective, are difficult to convey in a tactile diagram. They should be avoided wherever possible, and the verbal narrative must articulate the distinction between the simple diagram and the complex quality of the work itself. The process of simplifying and breaking down an image varies, depending upon whether it is a painting, sculpture, or work of architecture. However, you must keep in mind that the tactile diagram is merely a map. In the process of simplifying an image, distortions will occur. This happens, for example, when parts of an image are emphasized to convey a point. Sometimes it is necessary to emphasize specific parts of an image to create tactile points of reference; this can help guide the user through a diagram. Furthermore, our hands, like our eyes, need to feel a shape that is exaggerated in order to get a sense of the actual qualities of the work.
Additionally, sometimes proportions are distorted and objects or figures are moved slightly in order to make the tactile information more accessible. In general, these kinds of distortions are incorporated into the diagram to make it a successful communication tool. Once again, the tactile diagram is not and should not be considered an exact reproduction of the actual image.
Cubism can be a very difficult concept to portray. In this tactile diagram of the painting Ma Jolie by Picasso, we have only depicted certain aspects of the painting, emphasizing the most important elements with thick lines and textures.
Using Lines to Describe the Basic Shapes
Once you have decided which objects to include and which to omit, you must transform these objects into simple shapes. All objects are outlined. Generally, a thin line is used to describe shapes. In paintings and maps, a thin line describes the outer edge, or border, of the image. In addition to this outlining function, lines convey other types of information. There are three other types of lines used in this way. Thick lines emphasize specific objects, or they describe the shapes that are closest to the viewer. For example, an overlapping shape may be thickly outlined to show that it is the most prominent form. Broken lines and dotted lines are used to represent imaginary lines, such as an axis or the position of a dome in an architectural ground plan.
It is important to show which shapes overlap other shapes. The only completely closed shape is the overlapping shape, the one closest to the viewer. Leave about one-eighth inch of space around the shape that overlaps the shape behind it. Conversely, the overlapped shape is not closed. There should be one-eighth inch of space around all intersecting lines, making the overlapping line the most prominent line. The outline of the overlapped shape should not touch the outline of the shape that overlaps it. In some cases, overlapping shapes can be slightly separated. This separation makes the diagram easier to read, because it enables the user to distinguish the different forms. Here again, a slight distortion serves to make the image more accessible.
|This diagram illustrates the use of thin and thick lines in a map. The thinly outlined areas represent the countries in Europe as we know them today. The thickly outlined areas represent the areas where prehistoric images and artifacts have been found.|
|This diagram illustrates overlapping objects on a table. The two objects in the background are thinly outlined because they’re farther from the viewer, while the two objects in the foreground are thickly outlined because they’re closer.|
|This diagram illustrates the ground plan of St. Peter’s, in Rome. The dotted lines represent imaginary lines—the vertical and horizontal axes. The solid areas represent the building’s thick walls.|
Breaking Down Images into Multiple Diagrams
A tactile diagram can convey only a limited amount of information. Therefore, a complicated image may need to be broken down into two to four diagrams. When multiple diagrams are used to illustrate one image, their tactile vocabulary must be consistent. For example, the same line widths and patterns must be maintained throughout the diagram sequence. In the sequence, there should be a gradual progression from basic information to more detailed information. The first diagram should be the simplest, and the final one the most complex. Depending upon the subject matter and the information you want to convey, there are several ways to break down an image. The discussion below suggests options for various media.
There are two common methods of translating a complex two-dimensional image, such as a painting or drawing, into a diagram sequence.
Background, Foreground, and Composite Views
The most common way to break down an image is to separate the background and foreground, or the ground and figures, illustrating them in two separate diagrams. The third diagram consolidates these two preceding diagrams in a composite view of the complete image. With this method, you introduce the visual information in a series of steps. The final diagram should sum up the details in the preceding diagrams. This enables the user to assemble, piece by piece, a mental image of a highly complex work of art. This method also helps the user understand the relationship of the objects or figures to one another and to the surrounding space. A good example is The Gathering of the Manna we saw earlier.
A Highly Schematic Diagram Followed by
Enlarged Detail Views
The schematic diagram presents a simple view of the entire composition. This view shows the placement of the objects within the space and their relationship to one another. After a basic sense of the composition is established, you can illustrate in subsequent diagrams selected elements in greater detail.
|To illustrate this point, we use Hope II by Gustav Klimt.|
|Figure A is a very simple, schematic drawing of the objects in the painting.|
|Figure B illustrates another detail: the top half of the painting.|
|Figure C illustrates a third detail: the bottom half of the painting. Note the pattern around the edge that indicates that the image is a detail.|
Enlarged Detail Views
Detail views of important visual features are an effective way of conveying information on works in all media. Detail views should utilize the same tactile vocabulary as the diagram illustrating the complete work. When a detail diagram serves as an enlarged view of one aspect of a diagram illustrating the complete work, detail lines should describe its outer edges. Detail lines, which are essentially cutaway lines, inform the user that the image is a detail. The arrows of the detail line point outward, indicating that the illustration is cut along this line. The arrows point in the direction in which the actual image would continue beyond the detail.
It can be helpful to include, in one of the corners of the detail diagram, a small schematic illustration of the whole image. In this small illustration, a patterned area identifies the part represented in the detail. This point of reference allows the user to place the visual information in context.
One example of this approach is the tactile translation of Hope II, by Gustav Klimt. You can see detail lines in all diagrams. In figure b, the arrows point downward and to the left and right, showing that the painting continues beyond the detail lines in those directions. In the other figures, the detail lines serve the same purpose.
It is usually not necessary to break down sculpture into several diagrams, but you may choose to depict the same sculpture from different points of view. For example, it is frequently useful to include a detail view of a figure's face. In these tactile translations of the Riace Bronze Warriors, figure A shows the sculpture from a three-quarter frontal and back view. Figure B is a detail of the figure's head.
Generally, architecture requires several diagrams to convey the different kinds of information present in this art form. The first diagram illustrates the ground plan of the building. The plan may include the surrounding grounds, such as gardens, if they are an integral feature of the site. When illustrating a ground plan, the entrance should be placed nearest the bottom of the diagram. This is the part of the page closest to the person reading the diagram. The verbal narrative guides the person through the ground plan as though he or she is actually walking through the building. Accordingly, the narrative begins at the bottom of the diagram and progresses upward toward the top. The second diagram illustrates a sectional view of the building. In this kind of illustration, the interior of the building is visible. You might select a longitudinal or transverse section, depending on the building’s structure. The architectural elements illustrated in the section view must be consistent with the architectural elements illustrated in the ground plan. In the third diagram, an elevation of the building’s façade is illustrated. The elevation should be a strict frontal view.
We use three tactiles to represent the Pantheon in Rome.
|Figure a illustrates the ground plan. The dotted lines represent imaginary lines that show the location of the oculus in the ceiling and the steps outside the building. The solid circles and small outlined squares represent the location of columns. The patterned area around the periphery represents the thick wall of the building. At the bottom center of the diagram an arrow points upward to show the entrance. The arrow in the lower left corner is a compass pointing north, and the short line above it represents the height of a person in relation to the height of the building.|
|Figure b is a longitudinal transverse section of the building. You can see how this diagram correlates with the first diagram. At the top, the oculus is depicted by two dotted lines, and the columns are located in the same position as in the ground plan. The entrance arrow is on the left and the compass is in the lower left corner of the page.|
|Figure c shows the façade of the building. Again, you’ll notice the entrance arrow at the bottom center of the page and also the compass in the lower-left corner of the page. All three diagrams show the entrance arrow and the compass point.|
After all the objects have been reduced to simple outlined shapes, the forms are filled with patterns. When filling a shape with a pattern, there must always be one-eighth inch of space between the shape’s outer border and the pattern’s border.
Once you’ve drawn a simplified outline of the image, you’re ready to add patterns. Cut out each shape and place a pattern behind it, using the reproducible pattern sheets included in this book. An Exacto knife is the best tool for cutting out the shapes. Remember not to cut too close to the black outlines. Try to stay about one-eighth inch from the outline, as shown in the photographs below.
Once you’ve finished cutting out a shape, you’re ready to add a pattern. See the explanation of each pattern to help you choose the correct one for the object you are representing.
After you select the pattern you’d like to use, cut a section of it that will fit the shape you want to fill. Then tape that pattern to the back of your diagram. Now continue to the next shape, until you’ve completed the entire diagram.
Patterns serve several purposes, although basically, patterns differentiate objects from one another. For example, you cannot fill two objects placed next to each other with the same pattern if you want to differentiate them. Patterns can also depict different colors, or represent degrees of spatial recession. Smoother, flatter patterns can be used to depict objects farther away, while coarser and higher-relief patterns can depict objects that are closer to us. ABS uses six Tactile Patterns (plus solid black). You can print out and reproduce these pages of patterns to help you create tactile diagrams. What follows is an introduction to the patterns and to the labels and icons that ABS uses.