Paint by number (or painting by numbers) describes kits having a board on which light blue or gray lines indicate areas to paint, each area having a number and a corresponding numbered paint to use. The kits were invented, developed and marketed in 1950 by Max S. Klein, an engineer and owner of the Palmer Paint Company of Detroit, Michigan, and Dan Robbins, a commercial artist.
In children's activity books, simpler activities are often presented to children and are called color by numbers.
In 1951 Palmer Paint introduced the Craft Master brand which sold over 12 million kits. This public response induced other companies to produce their own versions of paint by number. The Craft Master paint-kit box tops proclaimed, "A BEAUTIFUL OIL PAINTING THE FIRST TIME YOU TRY."
Following the death of Max Klein in 1993, his daughter, Jacquelyn Schiffman, donated the Palmer Paint Co. archives to the Smithsonian Museum of American History. The archival materials have been placed in the museum's Archives Center where they have been designated collection #544, the "Paint by Number Collection", and are available to both the public and museum staff for research and exhibition purposes. Artifacts which establish Max Klein as the inventor and main merchandiser of these items are part of the collection.
In 1992, Michael O'Donoghue and Trey Speegle organized and mounted a show of O'Donoghue's paint by number collection in New York City at the Bridgewater/Lustberg Gallery. After O'Donoghue's death in 1994, the Smithsonian Institution's National Museum of American History exhibited many key pieces from O'Donoghue's collection, now owned by Speegle, along with works from other collectors in 2001. Since then, the vintage kits and paintings have experienced a resurgence through yard sales and eBay auctions.
In 2008, a private collector in Massachusetts assembled over 6,000 paint by number works dating back to the 1950s from eBay and other American collectors to create the Paint By Number Museum, the world's largest online archive of paint by number works.
In 2011, The Museum of Modern Art in New York accepted four early designs of paint by number by Max Klein for its Department of Architecture and Design, donated by Jacquelyn Schiffman.
In May 2011, Dan Robbins and Palmer Paint Products, Inc., together developed and brought to market a new 60th-anniversary paint-by-number set. This collectors' set was created in memory of the survivors and those who had lost their lives on September 11, 2001, and depicts the Twin Towers standing in spirit across the Manhattan skyline. A portion of the proceeds of this set is being donated to the charitable organization Voices of September 11th.