But the dots were less depersonalizing than you might initially think. One frequent misapprehension about Pop art, and Lichtenstein’s work, is that because the painter adopted the language of mechanical reproduction, his works are essentially mass-producible themselves. I certainly espoused this view after seeing the 1990s retrospective.

The National Gallery show, however, in going beyond the stereotypical image of Lichtenstein, shows that the painter was in many ways a traditionalist: His paintings are old-fashioned representations in paint, on canvas, with a physicality that can’t fully be communicated in reproductions. Even the dots have a presence (as a catalogue essay by Harry Cooper, the National Gallery’s contemporary art curator, illuminates). The first three works you see as you enter the show emphasize this physicality, from the painterly surface of the ceiling in “Artist’s Studio ‘Look Mickey’ ” (1973) to the textured, slightly scored silver panel in “Entablature” (1975) to the vivid corporeality of “Galatea,” (1990) a three-dimensional sculpture cutting the artist’s signature sensuous black lines through the gallery air.

Lichtenstein’s work is not simply about conventions of reproduction like print screens and dots; it’s about the artistic depiction of those conventions. And what animates it is not solely its inherent social criticism, but the tension between the individuality of the painter’s hand and eye and the impersonality of what he uses them to illustrate. This tension runs through the whole show, and is what made it such a delight, even a revelation.

It’s always fun to have a show make you reevaluate an artist you thought you knew. After the 1993 retrospective, I came away feeling Lichtenstein had had a burst of fecundity in the 1960s and ended up repeating himself or looking in vain for a way to get back to that initial energy. The current show, by contrast, shows him dumping a huge bag of tricks out on the table in the ’60s and continuing to play with them, examine them, and follow them ever further to new solutions, for the rest of his life.

The biggest “trick” involved the comic-book subject matter and style that comes into the work in 1961 with a bang and the piece “Look, Mickey.” Nothing is quite what it seems in a Lichtenstein painting, and this image of Mickey Mouse and Donald Duck turns out to have been quoted not from a comic book, but from a children’s book illustration: Lichtenstein actually returned it from a more painterly idiom to a comic-book one, with three-color “printing” and an uneven grid of red dots on Mickey’s face applied with a dog grooming brush. “Look, Mickey” also leaves, in the underlying pencil sketches, traces of the human hand involved in making this supposedly mechanical image, and in subtly altering it from its original form — something Lichtenstein did in all his comic-based work.