Francisco de Goya, 'Doña Isabel de Porcel', before 1805

A woman sits or stands, the top half of her body swung to our left, as she turns towards someone or something outside of the picture. She is dressed like a maja, a woman typically from the lower classes whose clothes became fashionable among royalty and aristocracy in Spain during the late eighteenth and early nineteenth centuries. She wears an elaborate shawl and headdress of cascading black lace, known as a mantilla, held back off her face by a comb decorated with a large rosette of ribbons (a caramba).

The sitter is Doña Isabel de Porcel, according to an inscription on the back of the original canvas. Goya exhibited a portrait of her at the Royal Academy of Fine Arts in Madrid in 1805. A year later he painted a portrait of her husband Antonio, the Secretary of State for Spain’s American Colonies, whom she had married in 1802. The two portraits seem to have remained together until around 1887, but it’s unlikely that they were intended as a pair: they were painted in consecutive years, differ in dimensions, and Antonio’s was on panel (his portrait ended up in the Jockey Club in Buenos Aires where it was destroyed by fire in 1953).

When an X-ray image was made of this painting during conservation treatment in 1980, another portrait was found underneath. Doña Isabel was painted directly over the other portrait, seemingly of a man wearing a waistcoat and striped jacket, without hiding it with a new priming layer. You can just make out the dark curve of his eyebrow on Doña Isabel’s chin, and the stripes of his jacket are visible through her right sleeve. There is no varnish layer – normally the last stage in completing a painting – between the two portraits, suggesting it probably didn't leave the artist’s studio before being painted over. There’s no dirt layer between the two portraits either, so Doña Isabel must have been painted very soon after the man underneath, whose fashionable costume points to a date in the mid- to late 1790s. Artists often reused canvases, especially during periods of political upheaval when canvases were hard to come by and patrons fell in and out of favour, and Goya was no exception.

Despite being painted with great flair – look, in particular, at the distinctive zigzag patterns that brilliantly convey the transparency of the lace – and long considered one of Goya’s most dazzling portraits, doubts have recently been cast over whether it really is by Goya.