Clothing appeals to cuilco, conceptually. They are a private people, not given to openness about themselves, and the idea of concealing the body is attractive to them. However, physical factors have limited their use of clothing historically: the warmth and humidity of their homeworld, combined with their skin’s need for fresh, damp air, and exacerbated by the three-dimensional nature of their environment and their rapid travel past and through vegetation (making any form of loose, draping clothing worse than useless), have made clothing largely impractical for them. However, clothing does nonetheless have a long and rich place in many of their cultures; clothing has been worn as armour, and for many ritual purposes both within their religions and in general society. The general theme has been that clothing is abnormal, something temporarily worn to signify the special nature of an event. At least, that has been the case for most societies – cuilco on colder and drier planets, or in the arctic regions of the homeworld, have long worn clothing more regularly.
In the absence of clothing, cuilco self-decoration has focused on the body. Painting (limited in extent due to the need to keep the skin open to the air), dyeing (cuilco skin temporarily changes colour to some extent in reaction with some chemicals, without becoming damaged) tattooing, scarification, piercing, and more extreme modifications have all been practiced. However, cuilco simply are not prone to ‘identificatory’ behaviour – they do not wish to stand out. They tend to feel that those who need to know them do know them without assistance, and those who do not know them do not need to know them. Hence, body art has been minimal. Where noteable traditions of body art have existed, it has instead typically been to identify groups – each band might bear identical markings, for instance. Even so, this has not been common.
Displays of wealth have been more common than displays of identity. Jewellary has been common, both in piercings (particularly of the ears) and in bracelets/bangles/bracers/collars/belts/etc. Metal has been a particular obsession of the cuilco – in addition to being rare and shiny, it possesses a particular beauty for a species with echolocation. For this reason, hollow, resonant metal items have always been very popular (both as jewellery and for adornment of spaces).
The most important use of clothing, however, is by members of monastic institutions. To prevent unauthorised relationships forming, members of the Orders wear masks at all time, except when permitted to remove them. These masks are almost entirely featureless, devoid of any distinguishing marks; traditionally they are made of metal, and this is still the case on formal occasions or when dealing with outsiders (where the mask also plays a role in intimidating others), but for daily wear modern masks are made of a lighter and more breathable material.
Cuilco art and architecture are too varied to make many generalisations about, from an aesthetic point of view. However, their echolocation does play an important role in their aesthetic preferences – on the one hand, its ability to judge texture and consistency more accurately than vision can has often lead to a greater emphasis on materials than on colours, while, on the other hand, the acoustic qualities of their sonar blur the distinction between visual art and music, and lead to an emphasis on both materials (eg metals) and structures (eg strings and skins) that resonate easily. Cuilco art is rare to be simply passively observed – the observer, through their active and autonomous use of sonar, is, as it were, the co-creator of the art. Observers without echolocation are likely to find cuilco aesthetics baffling and avant garde. Cuilco architecture in particular is wholly peculiar from a human perspective – large spaces (internal or external) are filled with a three-dimensional jungle of interlocking limbs, lines, lattices and lianas, often bedecked with hanging sheets and grills; rooms and ‘buildings’ occupy volumes, not areas, and often lack obvious coherent boundaries.