Whoever she was, "Susan Ellis" did not quite do things by the numbers, and good for her. What she ended up with would have looked fine in the family room, or over the mantel. She deviated, and in a way, she is one of the heroes of "Paint by Number: Accounting for Taste in the 1950s," which opens today at the National Museum of American History.

Susan Ellis decided, while painting "Winter Shadows" -- one of the millions of paint-by-number kits sold to mid-century citizens of Eisenhower's burgeoning America -- that there should not be a car in front of the house, even though the instructions clearly told her there was. Nor, she improvised, should the fence follow the road.

And look at her strokes: hasty, even sloppy, resistant to formula. The painting somehow becomes hers, and she did what few paint-by-number artists seem to have done: She signed it in the right-hand corner.

This finished product of splendid crapitude -- one imagines it possibly wending its way through attics or basements or yard sales before winding up here, on loan and sanctified, in the nation's attic -- is displayed with two other "Winter Shadows."

Three renditions of the same house, same trees, same snow.

Three Americans who never met, and yet participated in a collision of consumer culture and artistic taste, in a nation that had newfound leisure time and nothing to hang over the sofas of its new tract houses. The other two "Winter Shadows," in an able expression of middle-class conformity, look almost alike, beguiling in their simple beauty and placid nonexistence. See how none of the elements -- branches, creek water, house -- seem to occupy the same optic realm. These other "Winter Shadows" aren't signed.

Which is not to say that paint-by-number enthusiasts were ashamed of their work. Curator Larry Bird said he found several signatures on different kit paintings in the process of putting the exhibit of some 200 paintings together; often tiny little initials or names would emerge when the paintings were dusted off and cleaned.

For we are a proud people, and not terribly original, and most of us don't know from art. Do-it-yourself is a patriotic mantra, and "Paint by Number" explores our sometimes troubling conceit to copy the style and craftsmanship of others and claim it, on some level, as our own. ("Every Man a Rembrandt" was a slogan to sell the kits, and a recurring exhibit theme that may or may not strike Smithsonian visitors as ironic.)

It's not a huge leap from painting by numbers to learning to play the organ in 37 easy lessons, or Hollywood test-marketing movies to make sure audiences like the endings. At a preview ceremony Thursday morning, Spencer R. Crew, the museum's director, even presented supportive test-market data: "86 percent of all museum visitors (polled) are very familiar with paint by number; 55 percent had done one themselves."

In other words, an exhibit by numbers as well.

Living "by the numbers" -- the painting craze launched this stern cliche -- has become our way of staying on message and assembling perfect lifestyles. The same years that Americans painted by numbers -- sales peaked with 12 million kits sold in 1954 -- they were also following picture-perfect instructions to cook gourmet meals, decorate Moderne-style living rooms, sew their own Vogue outfits, decoupage their keepsakes.

Painting by number unleashed a crafts obsession, and capitalized on the value in consensus. "The Last Supper" was a top seller. The man who drew the lines for the kit was a Polish concentration camp survivor who'd once been ordered to paint pictures of fruit on the wall of a prison dining room.

Naturally, the stewards of art and culture loathed the paint-by-numbers fad, and they didn't know that it would drop off significantly in popularity and sales, once television became a full distraction. Your dad was setting up an easel in the den, referring to himself, only half-jokingly, as an arteest. Everybody gets in on these hobby masterpieces, as a magazine advertisement suggested:

Let a typical family tell you why they prefer Craft Master Paint-By-Number sets. Mother: "Gives me the fine quality pictures I want to decorate my home. A value any woman appreciates!"

Father: "Mural-size pictures score plenty with me. Most relaxing hobby a man ever had."

Son: "1-2-3 is my speed. Mom says my pictures are super! Painting's wonderful fun!"

It didn't help that the paintings were, to the critic's eye, the very definition of lowbrow vapidity: supposed scenes of Paris sidewalks, brooks and knolls, mountains and trees, doggies and birds, Christ (the clean, non-bloodied, hair-conditioned Lord, sitting by the same creek as the old mill), fruits and veggies, portraits of baseball heroes, and, finally, proof of the Devil himself: sad clowns.

This is where, as usual, the Smithsonian steps in and finds feel-good common ground among all peoples, with its carefully modulated way of explaining us to ourselves. "Paint by Number" can be heavy-handed in its desire to sum up the pastime and demonstrate its usefulness to our cultural history. (At this rate, what's next? "Shaking Up and Starting Over: Etch-a-Sketch and the American '60s"?)

The exhibit concludes with the art form's role in kitsch nostalgia. A 1962 Andy Warhol riff on paint-by-number, "Do It Yourself (Flowers)," demonstrates how quickly the fad became its own punch line.

A digital print of "America's Most Wanted," the controversial 1994 painting by Vitaly Komar and Alex Melamid, is on hand to interject a side opinion about mass-market aesthetics: Based on surveys, the painting shows what Americans statistically want in their art, which puts George Washington in the middle of a Hudson River School-style backdrop, with deer, a family of three and a yawning hippopotamus.

At Thursday's preview, the father of paint-by-number, Dan Robbins, was on hand to tell stories about how, as head of the art department at Detroit's Palmer Show Card Paint Co. in 1951, he came up with the idea of taking children's painting kits to an adult market.

Robbins, who was in his mid-twenties at the time, recalled that it wasn't his idea, it was Leonardo da Vinci's: "He used to assign numbered parts of paintings to the people who were working for him. I thought that would be a good idea for people who wanted to paint their own pictures. Just follow the numbers. So I've always told people, 'Don't thank me, thank Leonardo.' "

Most of the pictures in "Paint by Number" are on loan from collectors who apparently foresaw a golden age for retro amateur art. Trey Speegle, who lives in Brooklyn, inherited most of his paint-by-number specimens from a friend, "Saturday Night Live" writer Michael O'Donoghue, who died in 1994. Speegle lent 20 pictures to the Smithsonian, "and to be honest, I'm trying to deacquisition some of them. I've learned a lot about what I have and what I don't have."

Speegle and other sentimental collectors were also invited to help paint, by numbers, a 29-by-18-foot banner hanging outside the history museum, facing the Mall. "I own 500 of them," Speegle enthused, watching Smithsonian Secretary Lawrence M. Small being hoisted up to the banner on a cherry picker, "but I've never painted one. I guess today I get my chance."

Everyone stared up into a pure, No. 7 bright blue sky. Small applied red paint to a designated, faintly outlined spot on the banner, which will eventually be completed to show a lighthouse by the sea. He painted the roof.

"I think it's all wonderful, and quite an honor," Robbins said, watching. "For the secretary of the Smithsonian himself to be here. And on top of that, he stayed in the lines."

Paint by Number: Accounting for Taste in the 1950s, at the National Museum of American History, 10 a.m.-5:30 p.m. daily, through Dec. 31. Call 202-357-2700.

The "Every Man a Rembrandt" slogan appealed to Americans' do-it-yourself nature, helping to popularize such paint-by-number kits as "Abstract No. 1," at left (finished version above), created by Dan Robbins for the Palmer Show Card Paint Co. in the 1950s.Un, deux, trois: "Eiffel Tower." A sendup by Andy Warhol, "Do It Yourself (Flowers)."