Tying one thing onto another does not necessarily imply tying on more of the same kind of thing (as in the nested structures discussed above). Khipu makers also sometimes tied on non-cord items such as tufts of wool, small sticks, rawhide tags, or even figurines. These might seem extraneous to cord media as such. But Galen Brokaw points out that mixing signs from several codes with separable reference systems is normal in many scripts: “Most complex media have a certain degree of semiotic heterogeneity. Alphabetic script is based on the principle of phonemic representation, but it also incorporates non-phonemic conventions such as Arabic numerals, punctuation marks, and spaces between words” (Brokaw 2010: 21). Extending the alphabetic example, one could point out that the mixed codes in heterogeneous sign-sets not only refer to different things (speech sounds, speech rhythms and intonations, and quantities) but also refer in different ways (letters being phonographic, numerals semasiographic and word spaces iconic). On khipus, sticks taken as likenesses of animals introduce iconic reference, while wool itself may be an indexical one.
Normal as ‘semiotic heterogeneity’ is, cord physicality seems a particularly open invitation to it, since cord is par excellence the means of binding varied objects together. This kind of heterogeneity seems most typical of post-Inka khipus. It reaches an extreme in Rapaz’s seriated-emblem khipus.
Linearity
Whatever else cords may be, they are linear right down to their atomic level (raw fiber). Tim Ingold could have made them a key case in his book Lines, on the way cultures construe linearity (Ingold 2007).
Khipu students have long wondered whether cord lines might not have served iconically to represent paths in spatial relationships. It is an Andeanist commonplace to comment that the ceque pattern of ritual lines radiating out from the Inka sacred city of Cuzco, with shrines forming nodes along them, looks like a giant khipu laid onto the landscape.
Inca-linked informants often said cords supported narratives: dynastic history and genealogy, laws, chansons de geste and ritual protocols. The Aschers (1982: 75) pointed out that a narrative, considered as a sequence of stylized or generic speech events (strophe, episode, etc.) could be matched to the linear, segmented, discrete format of khipu. A cord series knotted with indicators of certain types of events and values for them would suffice to structure, for example, a dynastic chronicle — though not the necessarily phonological representation of specific words in it. Catherine Julien (2000: 11–13, 226–228) and Brokaw (2003) argue that Inka dynastic histories rendered from, or written by, Andean experts bear specific formal structures carried over from khipus. Far from the Andean orbit, Wassmann (1991 [1982]) provides a detailed ethnography of how a Sepik River group in Papua-New Guinea practices an elaborate sequence of ritual oratory based on a cord device.
Abercrombie (1998) has gone the farthest in asking us to see khipu cords as predominantly ‘pathways’. He regards cords as iconic maps or guides representing passages through space and/or time (‘chronotopographs’), or even trains of thought moving through a purely mental space such as hierarchy.
Three-Dimensionality
It has been noted (Cummins 1994) that, in part and in whole, khipus inherently are solids rather than pure lines. This allows tactile legibility, at least theoretically. One colonial source asserts that a blind man made and read an immense khipu as an aid to Catholic confession (Harrison 2002: 281). Experienced spinners can indeed recognize many structures by touch, but the central importance of color makes the idea of tactile legibility less plausible.
