Mary Cassatt trove surfaces

Mary Cassatt captured the essence of Gilded Age femininity in her beguiling portraits of mothers with children and young girls with pets in genteel domestic settings.

Cassatt also printed mirror images, or counterproofs, of these subtle portraits in pastel from 1905 to 1915, during her long career as a leading expatriate artist in Paris. Her prints -- one or two per portrait -- were then marketed by her Parisian dealer, Ambroise Vollard, and the images all but disappeared into private collections.

Now, a trove of 48 counterproofs of these portraits, uncovered in the estate of an unnamed French art lover, will be sold at prices ranging from $50,000 to $400,000 apiece -- or more than $7 million for the lot.

The collection went on view Monday at the Adelson Galleries in Manhattan and will continue through Jan. 14. It is billed as the first-ever show and sale of Cassatt counterproofs anywhere.

The images show mothers and naked infants in endearing poses, young girls with pensive expressions holding their lap dogs and women in fancy dresses and large bonnets.

The discovery of the counterproofs came as a revelation for Cassatt experts, showing the extent of her experimentation in the European technique perfected in the 18th century.

Only 22 counterproofs of Cassatt’s work had been known before, including half a dozen held by U.S. museums. No one knew of this cache until Adelson’s colleague, Marc Rosen, was called in by the French estate to examine the holdings several years ago. The estate has others that are not being put on the market now.