We trust Pat Murphy will take no offence if we refer to her as something of a legend in Irish film. The director of Anne Devlin and Nora returns to cinemas with a beautiful piece on the silk weavers of Uttar Pradesh in northern India.

Films concerning traditional crafts form a distinguished huddle in the Irish documentary tradition. Such studies need to connect with the mechanics and, without patronising or romanticising, offer some flavour of the society within which the artisans work.

Tana Bana pulls that trick off with great aplomb. The film takes us through a day in the life of the weavers. We meet the men at the loom, the designers of the saris, and the chaps who sell the garments. "Madam, whatever sari you wear looks really good on you," a universal salesman says to an older lady (as they all do).

It hardly needs to be said that the trade is threatened by computerisation and globalisation. Along the way, Murphy ties the new technologies in with the old. One of the designers now originates patterns on a computer. He later colours in a grid whose individual cells look eerily like pixels. (The cards that drove Victorian looms were, of course, among the earliest types of computer programme.)

Such connections are left to the viewer in a film that, while rich with luscious shots of fabrics, dye and crumbling architecture, remains rigorous in its focus on the aesthetics and economics of this ancient industry. It is a tribute to the film-makers that, though one is aware that many hours of footage must have been whittled down to create the film’s current lean shape, the scenes cut together with a fluidity that feels positively organic.

A closing myth concerning the Buddha connects Tana Bana to the ages. Evening falls. It will all soon start again. But for how long will the cycle repeat?