Shipbuilding may have brought prosperity to Dumbarton in the 19th century, but William Strang, born into a family of shipbuilders, was far more interested in the profile of people than that of ships.

Now the subject of a new exhibition at the National Galleries of Scotland, Strang, who by the early 20th century had become an etcher and portraitist of some considerable international renown, was born in Dumbarton in 1859 and educated at the town's academy before embarking on an artistic career that would take him far from his Clydeside origins. His work, now held in major galleries from our own Scottish National Gallery to the National Gallery in London and the Tate, is showcased in this diminutive but enlightening exhibition of his prints, a defining part of the early output of this very distinctive artist.

Strang worked predominantly in print for the first 20 years of his career after training with French artist Alphonse Legros, whose Realist style he would consistently emulate, at the Slade School of Art in London. He produced, over his lifetime, more than 750 original prints, largely etched, although he also used other methods of printmaking including mezzotint, lithography, woodcut, drypoint and aquatint.

Strang enrolled at the Slade in 1876 aged just 17 after having already spent a fruitless year apprenticed at William Denny & Bros, a firm of Dumbarton shipbuilders in which he had relatives. After four years of artistic study, he became an assistant on the engraving course on which he had studied, and began to make his commercial mark, publishing in journals and in increasingly well-received series.

Strang's drawing style was both robust and highly attentive to detail. He distributed his talent widely, from genre subjects (from social realism to the fantastical) to over 150 etched portraits of major literary and artistic figures of his time, including Rudyard Kipling and Thomas Hardy.

Hardy, indeed, was a frequent sitter for Strang, whose etchings, sketches and oils of the great 19th-century writer map the outward face of the man from the 1890s, when the two met, probably in the Arts Workers Guild in London, up until the artist's death in 1921. Indeed, as Hannah Brocklehurst, the National Galleries' Curator of Prints and Drawings, points out in the literature accompanying the exhibition, the two "shared similar concerns - Hardy's writing, like Strang's images, was both visionary and naturalistic and his characters, like many of the figures in Strang's compositions, were often the victims of declining social circumstance."

That preoccupation showed in etchings such as Strang's harrowing Despair (1889), a print of a young woman with hollowed eyes boring directly into the viewer, feeding her baby while a young boy sits slumped at the base of her chair in a bare-boarded room, empty and dark. Brocklehurst points out that it is Strang's use of sandpaper to create lines on the etching plate which has added to the deeply sombre atmosphere of this dark print.

Elsewhere, Strang used this skill in finding the right physical expression for his subject matter to more commercially successful effect in his illustrations for some of Rudyard Kipling's stories. If these could be both evocative and brutal, he also used his propensity for the fantastical in very successful illustrations for Sinbad The Sailor and Ali Baba And The Forty Thieves in 1896.

At the turn of the century, Strang moved away from etching - although he did return to it later in his career - to concentrate on painting. If Legros was Strang's overriding influence in his etching, his later painting (which is not covered in this exhibition) began to show the influence of Whistler. The French and Belgian symbolists, too, were important to Strang, and his mature style can be best seen in paintings such as his vibrant and distinctive portrait of Vita Sackville West, finely memorialised as Lady With A Red Hat (1918, now in Kelvingrove Art Gallery) with its bold and confident use of colour and its very distinct sense of time and place.

If his etchings sometimes plumbed dark and bizarre subject matter - often from his own dreams - his paintings fruitfully draw on the Old Masters, not least Hans Holbein the Younger and Rembrandt, yet with his own distinctive and innovatory style. It was work that had a psychological intensity and individuality that was all his own, and this small selection of his prints shows both the diversity and singularity of that vision.

Fair Faces And Dark Places: Prints And Drawings By William Strang (1859-1921), Scottish National Gallery, Edinburgh (0131 624 6200, www.nationalgalleries.org), October 18-February 15