A discussion of Impressionism should include a reference to Gustav Caillebotte. Caillebotte was an Impressionist painter himself; but more importantly, he was a patron to other painters. Many great works of the period are available to us because he willed his collection to the French government. His condition for the gift was that the paintings be displayed, not warehoused.
Caillebotte's collection can be seen in some of his paintings. This self portrait, is a fine example...
He painted this in his apartment. Notice what is hanging in the background?