Fortuny, Accordion, Sunburst: How Three Pleating Techniques Shape a Couture Garment

Not all pleats are the same craft. In haute couture, three techniques dominate the conversation: Mariano Fortuny's irregular silk plissé, the uniform accordion pleat, and the radiating sunburst pleat. Each is made differently, and each produces a distinct effect on a garment's structure, volume, and movement. Understanding how they work is the difference between seeing "a pleated dress" and recognizing a deliberate engineering choice in cloth.

Mariano Fortuny's Revolutionary Plissé: The Delphos Gown

Plissé is an ancient method—Fortuny's own account traces it back to Ancient Egypt—but it was Mariano Fortuny who, in the early 1900s, revolutionized it and consecrated it as a synonym of elegance, luxury, and sensuality. His plissé was obtained through a long manual process in which the fabric is folded back on itself, and the pleat, by its very definition, allows freedom and elasticity to both the fabric and the wearer.

How exactly did he do it? The honest answer is that no one outside the workshop fully knows. It is widely believed that such pleats could only be achieved when the garment was wet—quite possibly submerged under water—quickly followed by the application of heat to ensure the pleats kept their form. The technique sounds almost disarmingly simple; the results were anything but. Many Delphos gowns over sixty years old still maintain firm, flexible pleats today.

The Delphos gown, made of fine silk, is the technique's masterpiece. The silk was dipped many times to enrich the color from a neutral base, so that it changed tone according to light and the movement of the fabric. As the Metropolitan Museum's file on the dress puts it, the Delphos "exemplifies Fortuny's ability to transform something historical into a totally modern garment." The pleat invites the fabric to cling to the body's natural shape—movement and light, embodied in a fold.

Accordion Pleats: Uniformity and Fluidity

The accordion pleat is the workhorse of the family: symmetrical folds, each side of the pleat the same length, resembling the bellows of the instrument it is named for. According to the craft resource Made/in, accordion pleats are among the most common pleating styles, alongside side pleats and box pleats (in a side pleat, one side is shorter than the other so the pleat folds flat to one side).

Its construction can be done by hand or by machine. Machine pleating, as the New York Embroidery Studio explains, runs fabric through heated machines that shape it in the desired way—though this method is slightly less flexible than other forms, since it can only complete accordion, side, and sunburst type pleating.

Aesthetically, uniformity is the point. Because every fold is identical, the fabric gains consistent volume and a rhythmic texture that expands and contracts with the wearer's motion. Where Fortuny's plissé clings, the accordion pleat breathes in and out like its namesake, adding drama through regular, mechanical repetition rather than organic irregularity.

Comparative Typology of Haute Couture Pleating Techniques

The three techniques can be distinguished at a glance by asking three questions: how was it made, what does it do on the body, and what does it trace back to?

Three key haute couture pleating techniques compared
Technique	Creation Method	Visual Effect & Movement	Key Example
Fortuny's plissé	Long manual process; fabric folded back on itself, widely believed to involve wetting the garment (possibly submerged) followed by heat to fix the pleats. Exact process remains a closely guarded secret.	Irregular, fine folds that cling to the body's natural shape; freedom, elasticity, and a sensual drape.	The Delphos gown of fine silk, created in 1907; many examples over 60 years old still hold firm, flexible pleats.
Accordion pleat	Uniform, parallel folds of equal width, done by hand or run through heated machines; heat-pressing lasts only on polyester.	Resembles accordion bellows; consistent volume and rhythmic texture that expands and contracts with movement.	A common pleating style in haute couture for adding volume and movement (no single canonical garment).
Sunburst pleat	Pleats radiate from a central point via a tapered cardboard mold and heat-setting, narrow at the waist and widening toward the hem.	A dynamic, fan-like effect that adds dramatic flair and movement, especially to skirts and dresses.	One of the three pleat types achievable by machine pleating; used for radiating skirt designs.

Read side by side, the table shows why a designer chooses one over another: Fortuny's plissé for a clinging, body-tracing line; the accordion for even, breathing volume; the sunburst for directional drama that widens as it falls.