Walk on a sandy beach or a silted riverbed barefoot and you’ll leave behind intricate footprints. Take a mound of moist clay and press your fingers onto it. Again, what will be left are clear and detailed impressions of your fingers on the clay. The precise nature of the impression depends on many things, including the nature of materials used to make it. The process of making impressions was studied and used by the ancient people. Humans learned to create systematic impression-making mechanisms on the Indian subcontinent as early as in the Indus Valley Civilisation almost 5,000 years ago. Numerous plates and impressions have been found at various Indus Valley sites, particularly Harappa and Mohenjodaro.
The animal figures in the Harappa-Mohenjodaro seals are carefully sculpted in relief with a stylised yet recognisable presentation. Also on the seals are symbols that are thought to be the script of the language used at the time. The script is a story for another day, but the animal forms are indeed elegant. So how did the Harappans work with seals used in trade?
The impression of the plate on soft clay not only leaves a mirror image but also transforms it. For instance, a depression on the plate appears as a raised surface on the impression and vice versa. Note that the entire image is also laterally inverted. The seal thus produces a complex three-dimensional impression and its design was a matter of both imaginative prowess and mastery over materials. The ideas inherent in the process of seal making were developed by different human civilisations to solve a wide range of problems.
However, the reproduction of these impressions, especially large impressions, posed practical problems. The seals were often sent across to places far and wide. That their use was widespread is evidenced by the wide dissemination of Harappan seals — as far as Mesopotamia. Is it possible to produce multiple seals in a short span of time and send them to distant lands? How did the ancient people tackle the problem, especially when they felt the need to make larger, more elaborate impressions? In order to make large impressions, ancient humans produced stone cylinders, onto which carvings were made. When this compact cylinder was rolled out onto a bed of soft clay, a long rectangular impression was achieved. These seals have been found in multiple ancient cultures, which suggests that means to produce elaborate seals and their reproductions were in demand then.
The development of rollout seals also raised new questions. How could one produce large impressions, like the ones made by a cylindrical seal, but make the process cost-effective? One was through the invention of paper, a simpler material that is also easy to transport compared to clay tablets. Another development was that of pigments and inks, the making of which involved the isolation of coloured materials from nature, which were then mixed in a binder to produce a sticky substance that would stick the pigment powder to itself as well as other materials. Yet all of this had to be repeated by hand each time a replica was needed. Professional copy makers, now called scribes, were common in the medieval world. But their speed had limits. Was it possible to copy a page faster than the fastest scribe?
It appears, there is a way to do it. Take the layout, say of a large seal, and separate each symbol. Now make a separate seal for each symbol. In fact, make a separate seal for all possible symbols used in a particular culture. The method ensures that for any given sentence one wishes to reproduce, one has to only re-arrange the individual small seals without any gaps and then affix them to a hard backing board. This board, with the moveable seals, when inked and pressed onto a piece of paper will leave an impression of the entire layout. In such a system, one only needs to produce multiple blocks for each of the letters of the alphabet only once and then simply rearrange them to achieve a desired order of letters. Such a system, using metallic type blocks instead of ceramic seals, was developed in the city of Mainz in Germany and came into popularity during the production of Gutenberg’s Bible. We call this technology ‘moveable type’ today, and it was the basis for printing of books for a few centuries.
The Harappan seals also throw up another question — the abstract issue of the nature of representation itself. An artist may well ask questions about the many different ways of rendering an animal on a flat surface. Pablo Picasso did exactly that in a series of now famous drawings exploring the different abstractions of a bull.
So there you have it. Ideas in an ancient seal re-emerging through the ages to inspire technology and art, mixing in ways that are not immediately obvious, yet making themselves felt in every aspect of modern life.
Santanu Chakraborty is a Bengaluru-based engineer, scientist and photographer