Most of Barbara Hepworth’s late stringed sculptures invoke the sun and the moon. The theme began in 1966 when she made a small, solid gold work called Sun and moon [BH 417]. In her garden at Trewyn Studio in St Ives where she displayed and reflected on her work, Hepworth became acutely sensitive to the changing conditions of light produced by the sun and the moon. Speaking to Mervyn Levy in 1962, she recalled being amongst her sculptures at night:

One moonlit night, I wandered into the garden. In the pale, clear, silver light, the sculptures presented quite different aspects of their being from any which I had seen before. […] They have so many moods and faces.

In 1969, Hepworth made a pair of works in polished bronze and aluminium. Disc with strings (Sun) [BH 485] had strings arranged in a spiral pattern, criss-crossing the inside of the curved disc, while Disc with strings (Moon) had two overlapping sets of diagonal lines composed in a cascading formation. Two years later Three curves with strings adopted the same stringing pattern as Disc with strings (Sun), as did two closely related works made in the same year: Small Mincarlo, made in versions of aluminium [BH 523A] and brass [BH 523B], and Mincarlo [BH 526]. Owing to the close similarity of these works, Three curves with strings has at times been titled ‘Mincarlo’ but, uniquely amongst them, it was made from precious metal. Like Sun and moon, commissioned by Cornwall County Council as a gift for HM Queen Elizabeth II, Three curves with strings was also a commission. It was one of several small-scale works in eighteen-carat gold commissioned by the Morris Singer Sculpture Association Ltd in 1971. Besides Hepworth, Elisabeth Frink, Kenneth Armitage and Lynn Chadwick were amongst those sculptors who received a commission.

In Three curves with strings, Hepworth adopted the same format as Disc with strings (Sun) yet achieved more delicate, layered effects. Three curved polished discs with circular perforations are arranged back-to-back. One of these directly replicates Disc with strings (Sun), even using the same number of lines of string; a second disc also has spiralling strings while the third does not. The visual presence of strings is doubled by their reflection in the mirror-like surface, as are the circles when screened against a solid plane. The partial overlap between neighbouring perforations produces sightlines through to neighbouring compartments of the sculpture. The three curved discs cumulatively evoke a spherical shape with a planetary connotation. The suggestion of volumetric, massive qualities using nothing more than planes and lines of string was a continuation of Hepworth’s early uses of rolled brass and string in the fifties.

Later in life Hepworth paid occasional visits to the Isles of Scilly. Mincarlo is a remote, uninhabited granite rock noted as a breeding site for many species of birds including cormorants and puffins. Two other stringed sculptures of Hepworth’s, the Bryher works [BH 299, BH 305], made titular reference to an island in the Scilly archipelago: Bryher is a larger, neighbouring island north-west of Mincarlo. Hepworth explained her use of titles in 1970. ‘I don’t start with a title: I make a shape, and there may or may not be an association with it—but this comes afterwards.’ Hepworth gave the same appellation to a very different work a few years earlier, Two forms (Mincarlo) (1964) [BH 359], a slate carving composed from a pierced, upright form and an unpierced, recumbent one.