Question: When did Picasso make his best paintings?
About the article "Dora Maar au Chat", section "Descriptions of painting".

Candidate passages:
Picasso was one of 250 sculptors who exhibited in the 3rd Sculpture International held at the Philadelphia Museum of Art in mid-1949.
In the 1950s, Picasso's style changed once again, as he took to producing reinterpretations of the art of the great masters.
He made a series of works based on Velázquez's painting of "Las Meninas".
He also based paintings on works by Goya, Poussin, Manet, Courbet and Delacroix.
He was commissioned to make a maquette for a huge -high public sculpture to be built in Chicago, known usually as the "Chicago Picasso".
He approached the project with a great deal of enthusiasm, designing a sculpture which was ambiguous and somewhat controversial.
What the figure represents is not known; it could be a bird, a horse, a woman or a totally abstract shape.
The sculpture, one of the most recognisable landmarks in downtown Chicago, was unveiled in 1967.
Picasso refused to be paid $100,000 for it, donating it to the people of the city.
Picasso's final works were a mixture of styles, his means of expression in constant flux until the end of his life.
Devoting his full energies to his work, Picasso became more daring, his works more colourful and expressive, and from 1968 to 1971 he produced a torrent of paintings and hundreds of copperplate etchings.
At the time these works were dismissed by most as pornographic fantasies of an impotent old man or the slapdash works of an artist who was past his prime.
Only later, after Picasso's death, when the rest of the art world had moved on from abstract expressionism, did the critical community come to see that Picasso had already discovered neo-expressionism and was, as so often before, ahead of his time. 
After acquiring some fame and fortune, Picasso left Olivier for Marcelle Humbert, who he called Eva Gouel.
Picasso included declarations of his love for Eva in many Cubist works.
Picasso was devastated by her premature death from illness at the age of 30 in 1915.
At the outbreak of World War I August 1914 Picasso lived in Avignon.
Braque and Derain were mobilized and Apollinaire joined the French artillery, while the Spaniard Juan Gris remained from the Cubist circle.
During the war Picasso was able to continue painting uninterrupted, unlike his French comrades.
His paintings became more sombre and his life changed with dramatic consequences.
Kahnweiler’s contract had terminated on his exile from France.
At this point Picasso’s work would be taken on by the art dealer Léonce Rosenberg.
After the loss of Eva Gouel Picasso had an affair with Gaby Lespinasse.
During the spring of 1916 Apollinaire returned from the front wounded.
They renewed their friendship, but Picasso began to frequent new social circles.
Towards the end of World War I, Picasso made a number of important relationships with figures associated with Serge Diaghilev's Ballets Russes.
Among his friends during this period were Jean Cocteau, Jean Hugo, Juan Gris and others.
In the summer of 1918, Picasso married Olga Khokhlova, a ballerina with Sergei Diaghilev's troupe, for whom Picasso was designing a ballet, Erik Satie's "Parade", in Rome; they spent their honeymoon near Biarritz in the villa of glamorous Chilean art patron Eugenia Errázuriz.
After return from honeymoon, and in desperate need of money, Picasso started his exclusive relationship with the French-Jewish art dealer Paul Rosenberg.
As part of his first duties, Rosenberg agreed to rent the couple an apartment in Paris at his own expense, which was located next to his own house.
This was the start of a deep brother-like friendship between two very different men, that would last until the outbreak of World War II.
Khokhlova introduced Picasso to high society, formal dinner parties, and all the social niceties attendant to the life of the rich in 1920s Paris.
The two had a son, Paulo, who would grow up to be a dissolute motorcycle racer and chauffeur to his father.
Khokhlova's insistence on social propriety clashed with Picasso's bohemian tendencies and the two lived in a state of constant conflict.
During the same period that Picasso collaborated with Diaghilev's troup, he and Igor Stravinsky collaborated on "Pulcinella" in 1920.
Picasso took the opportunity to make several drawings of the composer.
In 1927 Picasso met 17-year-old Marie-Thérèse Walter and began a secret affair with her.
Picasso's marriage to Khokhlova soon ended in separation rather than divorce, as French law required an even division of property in the case of divorce, and Picasso did not want Khokhlova to have half his wealth.
The two remained legally married until Khokhlova's death in 1955.
Picasso carried on a long-standing affair with Marie-Thérèse Walter and fathered a daughter with her, named Maya.
Marie-Thérèse lived in the vain hope that Picasso would one day marry her, and hanged herself four years after Picasso's death.
Throughout his life Picasso maintained several mistresses in addition to his wife or primary partner.
Picasso was married twice and had four children by three women:  Paulo (4 February 1921 – 5 June 1975) (Born Paul Joseph Picasso) – with Olga Khokhlova  Maya (5 September 1935 – ) (Born Maria de la Concepcion Picasso) – with Marie-Thérèse Walter  Claude (15 May 1947 –) (Born Claude Pierre Pablo Picasso) – with Françoise Gilot  Paloma (19 April 1949 – ) (Born Anne Paloma Picasso) – with Françoise Gilot Photographer and painter Dora Maar was also a constant companion and lover of Picasso.
The two were closest in the late 1930s and early 1940s, and it was Maar who documented the painting of Guernica. 
Vincent van Gogh and Pablo Picasso are by far the best represented artists in the list.
Whereas Picasso became a wealthy man, Van Gogh (supposedly) sold only one painting in his lifetime, "The Red Vineyard", for 400 Francs (about $1600 in 2011) to the impressionist painter and heiress Anna Boch.
His seven paintings in the list below alone were sold for over million current dollars. 
Picasso was exceptionally prolific throughout his long lifetime.
The total number of artworks he produced has been estimated at 50,000, comprising 1,885 paintings; 1,228 sculptures; 2,880 ceramics, roughly 12,000 drawings, many thousands of prints, and numerous tapestries and rugs.
The medium in which Picasso made his most important contribution was painting.
In his paintings, Picasso used color as an expressive element, but relied on drawing rather than subtleties of color to create form and space.
He sometimes added sand to his paint to vary its texture.
A nanoprobe of Picasso's "The Red Armchair" (1931) by physicists at Argonne National Laboratory in 2012 confirmed art historians' belief that Picasso used common house paint in many of his paintings.
Much of his painting was done at night by artificial light.
Picasso's early sculptures were carved from wood or modeled in wax or clay, but from 1909 to 1928 Picasso abandoned modeling and instead made sculptural constructions using diverse materials.
An example is "Guitar" (1912), a relief construction made of sheet metal and wire that Jane Fluegel terms a "three-dimensional planar counterpart of Cubist painting" that marks a "revolutionary departure from the traditional approaches, modeling and carving".
From the beginning of his career, Picasso displayed an interest in subject matter of every kind, and demonstrated a great stylistic versatility that enabled him to work in several styles at once.
For example, his paintings of 1917 included the pointillist "Woman with a Mantilla", the Cubist "Figure in an Armchair", and the naturalistic "Harlequin" (all in the Museu Picasso, Barcelona).
In 1919, he made a number of drawings from postcards and photographs that reflect his interest in the stylistic conventions and static character of posed photographs.
In 1921 he simultaneously painted several large neoclassical paintings and two versions of the Cubist composition "Three Musicians" (Museum of Modern Art, New York; Philadelphia Museum of Art).
In an interview published in 1923, Picasso said, "The several manners I have used in my art must not be considered as an evolution, or as steps towards an unknown ideal of painting … If the subjects I have wanted to express have suggested different ways of expression I have never hesitated to adopt them.
"Although his Cubist works approach abstraction, Picasso never relinquished the objects of the real world as subject matter.
Prominent in his Cubist paintings are forms easily recognized as guitars, violins, and bottles.
When Picasso depicted complex narrative scenes it was usually in prints, drawings, and small-scale works; "Guernica" (1937) is one of his few large narrative paintings.
Picasso painted mostly from imagination or memory.
According to William Rubin, Picasso "could only make great art from subjects that truly involved him ….
Unlike Matisse, Picasso had eschewed models virtually all his mature life, preferring to paint individuals whose lives had both impinged on, and had real significance for, his own."
The art critic Arthur Danto said Picasso's work constitutes a "vast pictorial autobiography" that provides some basis for the popular conception that "Picasso invented a new style each time he fell in love with a new woman".
The autobiographical nature of Picasso's art is reinforced by his habit of dating his works, often to the day.
He explained: "I want to leave to posterity a documentation that will be as complete as possible.
That's why I put a date on everything I do."
During the Second World War, Picasso remained in Paris while the Germans occupied the city.
Picasso's artistic style did not fit the Nazi ideal of art, so he did not exhibit during this time.
He was often harassed by the Gestapo.
During one search of his apartment, an officer saw a photograph of the painting "Guernica".
"Did you do that?"
the German asked Picasso.
"No," he replied, "You did".
Retreating to his studio, he continued to paint, producing works such as the "Still Life with Guitar" (1942) and "The Charnel House" (1944–48).
Although the Germans outlawed bronze casting in Paris, Picasso continued regardless, using bronze smuggled to him by the French Resistance.
Around this time, Picasso took up writing as an alternative outlet.
Between 1935 and 1959 he wrote over 300 poems.
Largely untitled except for a date and sometimes the location of where it was written (for example "Paris 16 May 1936"), these works were gustatory, erotic and at times scatological, as were his two full-length plays "Desire Caught by the Tail" (1941) and "The Four Little Girls" (1949).
In 1944, after the liberation of Paris, Picasso, then 63 years old, began a romantic relationship with a young art student named Françoise Gilot.
She was 40 years younger than he was.
Picasso grew tired of his mistress Dora Maar; Picasso and Gilot began to live together.
Eventually they had two children: Claude, born in 1947 and Paloma, born in 1949.
In her 1964 book "Life with Picasso", Gilot describes his abusive treatment and myriad infidelities which led her to leave him, taking the children with her.
This was a severe blow to Picasso.
Picasso had affairs with women of an even greater age disparity than his and Gilot's.
While still involved with Gilot, in 1951 Picasso had a six-week affair with Geneviève Laporte, who was four years younger than Gilot.
By his 70s, many paintings, ink drawings and prints have as their theme an old, grotesque dwarf as the doting lover of a beautiful young model.
Jacqueline Roque (1927–1986) worked at the Madoura Pottery in Vallauris on the French Riviera, where Picasso made and painted ceramics.
She became his lover, and then his second wife in 1961.
The two were together for the remainder of Picasso's life.
His marriage to Roque was also a means of revenge against Gilot; with Picasso's encouragement, Gilot had divorced her then husband, Luc Simon, with the plan to marry Picasso to secure the rights of her children as Picasso's legitimate heirs.
Picasso had already secretly married Roque, after Gilot had filed for divorce.
This strained his relationship with Claude and Paloma.
By this time, Picasso had constructed a huge Gothic home, and could afford large villas in the south of France, such as Mas Notre-Dame-de-Vie on the outskirts of Mougins, and in the Provence-Alpes-Côte d'Azur.
He was an international celebrity, with often as much interest in his personal life as his art.
In addition to his artistic accomplishments, Picasso made a few film appearances, always as himself, including a cameo in Jean Cocteau's "Testament of Orpheus".
In 1955 he helped make the film "Le Mystère Picasso" "(The Mystery of Picasso)" directed by Henri-Georges Clouzot.