We're in the paper lab at the gallery where, for the last year, Treacy has been carefully restoring etchings, mezzotints and lithographs by Romantic-era French and English artists. "Paper is like skin," she says. "You can't stop it from aging but you can slow it down. Artists from the late 1700s to the early 1900s tended to use good quality papers and inks, so we can wash everything safely. Then we air dry them, humidify them, put them in the press for a week or so, mount them and send them downstairs to be framed."
Peter Raissis, the gallery's curator of European prints, explains that this 1781 mezzotint by Henry Fuseli is the oldest in the show. He indicates the figure of Ezzelin. "Isn't that a very Romantic kind of pose?" he says. "And the dungeon, the hourglass, the crucifix - it's exactly like the English Gothic novel of the late 18th century.
"Fuseli had very bizarre, kinky overtones to his work - like the way the victim's eyes are bound and her breasts are exposed. But that's why he's so great too. He's such fun to look at."
Printmaking in the Age of Romanticism is the gallery's chance to show off its collection of more than 150 prints from artists including Turner, Blake, Géricault and Delacroix. Emerging in the late 18th century, Romanticism, Raissis explains, is a very broad church. "It's not a coherent style or doctrine, but the core thing is the idea that artists are free to express private experience, emotion, fantasy. There's an interest in sublime landscapes, nature in its more extreme moods, wild animals. It's a reaction to the 18th century Age of Reason - in a way, they praise irrationality."
The show includes Fuseli's Shakespearean scenes of fairies and witches; William Blake's fevered biblical imaginings; John Martin's Cecil B DeMillean apocalypses; JMW Turner's Elysian landscapes; and Eugène Delacroix's monumental lithograph of a heroic tiger.
Raissis says that Romantic artists turned to printmaking for its expressive possibilities but also to further their careers. "Turner, for example, was aware that printmaking was a medium through which he could broaden his reputation and make money. It was also used as a vehicle of dissent: for example, Daumier, the French political satirist, distributed prints to criticise the current regime."
While prints were often made by the artists themselves, others were executed by no less talented journeyman engravers. Raissis points to an intricate etching based on a Turner painting. "Phenomenal skill goes into creating something like this. It would take 20 times as long as the original painting, because these guys were having to sit there with little chisels on a piece of copper trying to translate the vaporous washes of a watercolour."
Nevertheless, Romanticism's main legacy to art history, Raissis says, is the elevated position that "great artists" enjoy to this day. "The idea that artists are creative geniuses being true to their vision - all of that stuff is pure Romanticism."