The fishtail setting — also known as the fishtail prong or French-cut prong — is a variation of the prong setting in which V-shaped grooves are incised into the metal at the base of each prong or along the bearing edge that cradles the stone. The resulting notched profile, when viewed from above or at an angle, resembles the forked tail of a fish, lending the technique its common name. Beyond its decorative function, the bright-cut facets created by the graver reflect ambient light, visually lightening the metalwork and drawing the eye toward the stone rather than the setting.

Construction and Tools

A fishtail setting is executed with a graver — typically a flat or onglette graver — or a bright-cut tool, both of which are pushed or drawn through the metal to remove a thin curl of material and leave a polished, angled wall behind. The V-shaped cuts are made symmetrically on either side of each prong base, or at regular intervals along a continuous bearing edge in multi-stone configurations. The angle and depth of each cut must be carefully controlled: too shallow and the decorative effect is lost; too deep and the structural integrity of the prong is compromised, increasing the risk of stone loss over time.

The technique demands a steady hand and considerable experience, as the cuts are made in precious metal — historically platinum or white gold in the Edwardian and Art Deco periods, yellow gold in earlier Victorian work — that cannot be easily corrected once removed. In contemporary bench practice, the fishtail cut is considered a mark of skilled hand-engraving and is rarely replicated convincingly by machine.

Historical Context

The fishtail setting reached its fullest expression during the Edwardian period (approximately 1901–1915) and the subsequent Art Deco era (roughly 1920–1939), when platinum's strength allowed jewellers to reduce the mass of metalwork to an unprecedented degree. Delicate, lace-like settings in platinum — often combining fishtail prongs with millegrain borders, knife-edge shanks, and fine engraving — became the hallmark of leading Parisian and London workshops. The fishtail cut complemented the geometric sensibility of Art Deco design particularly well, its crisp V-forms echoing the angular motifs prevalent across the style.

In the Edwardian context, fishtail prongs frequently appeared in garland-style (guirlande) settings for diamonds and old European-cut stones, where the openwork metalwork was intended to appear almost invisible, maximising the impression of stones suspended in light. The technique was also applied to calibré-cut coloured stones set in channel-like rows, where the bearing edge rather than individual prongs received the decorative cuts.

Relationship to Related Techniques

The fishtail setting sits within a broader family of bright-cut metalworking techniques. Bright-cutting in its general sense refers to any engraving that leaves a burnished, reflective wall, and the fishtail cut is a specific, formalised application of this principle to prong and bearing construction. It is distinct from a standard channel setting, in which stones are held between two continuous walls of metal with no individual prongs, though fishtail cuts may be applied to the inner walls of a channel to add decorative detail. Millegrain — the row of tiny beads rolled along a metal edge — is frequently used alongside fishtail prongs but is a separate operation performed with a millegrain wheel rather than a graver.

In the Trade and Contemporary Use

Among antique and estate jewellery specialists, the presence of hand-cut fishtail prongs is a positive indicator of period workmanship and skilled bench practice. Reproduction and revival pieces in the Edwardian or Art Deco style routinely incorporate fishtail settings as a period-appropriate detail, and the technique remains taught in advanced bench jewellery programmes. When assessing a piece, gemmologists and appraisers note whether the fishtail cuts are hand-engraved — identifiable by subtle variation between individual cuts — or machine-pressed, which produces a more uniform but shallower profile.

From a durability standpoint, a well-executed fishtail setting presents no greater risk than a standard prong setting of comparable gauge. Poorly executed cuts, however, can create stress points that accelerate prong wear, making periodic inspection by a qualified bench jeweller advisable, particularly for stones set in rings subject to daily wear.