Writing a letter isn’t the most common of activities these days, but when you do put pen to paper, the envelope is perhaps the least tedious part of the process. That wasn’t always the case, though. Before the days of envelopes, letterlocking was the go-to method to ensure your letter arrived at its destination without any tampering. These locking techniques have withstood the test of time, preventing contemporary researchers from opening letters, now sealed for centuries. However, a team of MIT researchers have developed a way to virtually unfold locked letters, revealing their secrets.

A letter is “locked,” so to speak, through a series of folds that would deter messengers – or anyone who intercepted a letter – from peeking at its contents. With this process, the letter itself become its own envelope, not dissimilar to the rudimentary ways you might have folded notes to pass in class a child. For centuries, letterlocking was a common, daily practice right up until mass-produced envelopes became popular in the 1830s.

Thousands of letters kept in museums and collections around the world remain locked, as it would be too dangerous to unfold them. So, researchers have had to guess at the contents of letter or commit to destroying a letter by cutting it open.

That was until a recently published report in Nature Communications revealed that a team of MIT researchers, led by MIT Libraries conservator Jana Dambrogio, have found a way to virtually unlock letters through x-ray microtomography.

While x-ray technology to study historical documents, like scrolls or documents only folded once or twice, is relatively common, locked letters have remained less studied due to their difficult nature. But with the help of a medical scanner, which can produce a three-dimensional x-ray image, researchers created algorithms to virtually flatten a locked letter. Through this process, researchers can not only know the secrets held in sealed letters but also better understand the various techniques used to lock letters.

Over the course of a few years, researchers studied 250,000 letters to create the “first systematization of letterlocking techniques.”

Of particular interest to researchers in this process was a trove of more than 3,000 300-year-old letters that were collected by a European postmaster. Known as the Brienne Collection, the letters were undeliverable and collected by the postmaster. Of its letters, 2,571 were opened while 577 were sealed providing researchers with excellent specimens to study. In examining this collection and other letters, researchers were able to categorize folding techniques allowing them to more quickly unfold the letters using their algorithms.

Research laid out in the report has the ability to accelerate a research process that previously could take years. For instance, it took researchers and scholars a decade to understand the intricate spiral locking technique Mary, Queen of Scots employed to send a secure letter to her brother-in-law Henry III, King of France in 1587 just hours before she was beheaded. Armed with their new virtual unfolding technology, it took MIT researchers just days to unfold the letter and reveal its secrets.

“Sometimes the past resists scrutiny,” said the MIT team. “We could simply have cut these letters open, but instead we took the time to study them for their hidden, secret, and inaccessible qualities. We’ve learned that letters can be a lot more revealing when they are left unopened. Using virtual unfolding to read an intimate story that has never seen the light of day—and never even reached its recipient—is truly extraordinary.”

Since the death of Sir Hugh Lane in 1915, 39 paintings that belonged to the Irish collector have been at the heart of a rift between Britain and Ireland. Now, though, the National Gallery in London and the Hugh Lane Gallery in Dublin have come to an agreement that will put decades of back and forth behind them.

Born in Ireland in 1875 and raised in England, Lane established himself as an art collector and dealer in London before returning to his Irish roots in the early 1900s. While mounting exhibitions of modern art in Dublin, Lane amassed his own collection of “Modern Continental” artworks. Primarily consisting of works by French Impressionists, including Manet, Monet, and Renoir, Lane loaned his collection to the National Gallery in London in 1913. The following year, he became the director of the National Gallery of Ireland, but he died aboard the Lusitania alongside nearly 1,200 others when it was sunk by a U-boat off the coast of Ireland in 1915.

It was in his death that Lane’s collection became a point of tension between the two countries. Lane’s will, dated 1913, stated that the entirety of his collection should be left to the National Gallery in London, but the waters were made murky when a codicil was found in Lane’s desk at the National Gallery of Ireland. The codicil revealed that Lane had changed his mind and had decided that his collection would be left to the country of his birth for “the people of Ireland,” but the amendment was only signed and not witnessed.

Due to the non-binding nature of the codicil, the National Gallery in London laid claim to the artworks, but the saga of the collection was far from over. In the subsequent years, the home of the collection was contested and in 1956, Summer Day by Berthe Morisot was stolen from Tate Britain by two Irish students seeking to raise awareness of the issue.

In the late 1950s, Britain and Ireland began a series of compromises that saw certain artwork travel between London and Dublin while a number were given to what is now the Hugh Lane Gallery on long-term loan. Now, though, a deal struck between the National Gallery in London and the Hugh Lane Gallery hopes to put the matter to rest, at least for a while.

The two institutions have entered into a 10-year partnership that will see 10 paintings rotate between the galleries on a five-year basis while two paintings will stay in London and 27 stay in Dublin.

The paintings on rotation have been pre-grouped and dubbed “Group A” and “Group B.” The former will consist of The Umbrellas by Renoir, Eva Gonzales by Manet, Summer’s Day by Morisot, View from Louveciennes by Pissarro, and Don Quixote and Sancho Panza by Daumier, all of which are currently in London. Alternatively, Group B includes Music in the Tuileries Gardens by Manet, Beach Scene by Degas, The Mantelpiece by Vuillard, Lavacourt under Snow by Monet, and Avignon from the West by Corot, which are all now in Dublin.

The Duc d’Orléans by the Studio of Ingres and Beheading of John the Baptist by Puvis de Chavannes will remain at the National Gallery in London. “In the spirit of partnership” these paintings will receive updated labels that will read: “Sir Hugh Lane Bequest, 1917, The National Gallery, London. In partnership with the Hugh Lane Gallery, Dublin.” Meanwhile, more than 2-dozen works will remain in Dublin, including works by Gustave Courbet, Jean-Léon Gérôme, and Jean-Baptiste-Camille Corot.

“This partnership is a brilliant example of cooperation in the cultural sector,” UK Culture Secretary Oliver Dowden said in a press release. His sentiments were echoed by Hazel Chu, Lord Mayor of Dublin, who said that the agreement “represents a unique cultural collaboration” between the two galleries, the two cities, and the two countries.

Sotheby’s New York has secured the rights to consigning the latest trove of a private art collection to hit the market, belonging to the late Texan heiress and rancher Anne Marion, who died last year at the age of 81.

The collection, which is valued at over $150m, is rich in works by American postwar artists like Andy Warhol, Clyfford Still, and Roy Lichtenstein. It will be sold across a total of eight sales in several categories, including 20th century art, American art, Old Masters, and Jewellery.

Marion was a fourth-generation heiress who owned the Burnett Oil company, as well as Burnett Ranches, which are among the most storied family-run businesses in Texas that include the legendary Four Sixes ranch. The companies were founded by her great grandfather but it was Marion who went on to expand the business empires and at one point amassing a net worth of over $1 billion that made her one of the country’s highest profile art patrons.

Marion also co-founded the Georgia O’Keefe Museum in Santa Fe and was an avid art collector. Her widower and fourth husband John Marion was an auctioneer and chairman at Sotheby’s. Marion’s collection spans several categories but the bulk of the value lies in Warhol’s “Double Elvis” (1963, est $20-$30m), which shows the singer as a gunslinging cowboy, as well as Richard Diebenkorn’s 7ft “Ocean Park No. 40” (1971, est $20-$30m) and Clyfford Still’s “Painting No. 1 (PH-125)” from 1948 (est $25m-$35m).

Roy Lichtenstein’s 1977 painting Girl with Beach Ball II, from the artist’s Surrealism-inspired period, is expected to sell for $12m–$18m. Its counterpart, Girl with Beach Ball III, is in the permanent collection of the National Gallery of Art in Washington, D.C.

Additionally, works by Franz Kline, Gerhard Richter, Robert Motherwell, Wayne Thiebaud, and Kenneth Noland sell at values between $4 million and $20 million. The pandemic has placed major estate collection sales of this value on hold, but with works such as these, the Marion collection is expected to comfortably match postwar trophy pieces with competitive buyers.

John Marion is best remembered for his role in selling of some of the most high-profile works ever to come through Sotheby’s, like Vincent van Gogh’s Irises (which sold for $53.9m), Pablo Picasso’s Yo Picasso ($47.9m), and Au Lapin Agile ($40.7m).