Putting together a major show these days takes the skills of a diplomat and the wallet of a banker. “The cost of a big exhibition such as ‘Monet in Normandy’ stems mainly from insurance and shipping; museums generally don’t charge hefty fees to lend works of art. But obtaining loans can be difficult for other reasons, such as the physical condition of a painting, or its popularity or importance. Some museums are reluctant to lend their signature works.”