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I thought I'd talk some more about the difference between an artist at the top of his game, and one who's in decline. Obviously everybody winds down with time, that's nothing to be ashamed of, but I thought if we could isolate what that decline consists of, we might be able to take some steps to slow it down in our own work.
In my opinion an artist at the peak of his form is more likely to be aware of how weird the world around us is. He'll do a gag about sleeping but for him the real gag is that we sleep at all, and how strange the idea of sleeping is. Think about it! For a third of every day we lie flat as a board under a cloth which might have obsessive patterns on it, all the time happily clutching a pillow or a teddy bear. That's truly funny...all the more so because it's real.
In the example above (click to enlarge), it seems like the artist is also mocking the idea of bedrooms. When you think about it, it is kind of funny that we set aside a whole room to sleep in, and that we decorate it so differently than we do the rest of the house. Catch the low, ignorantly-executed window, and the way Mutt looks bunched up on the extreme edge of the bed. Those red spots are hilarious, as are the fez and the gloves!
There's also something funny about the minimal staging: a pleasantly unconscious horizontal friend, a low ceiling, a dopey chair, a low window, another planet outside the window (the Moon), a bed covered with obsessive dots, and Jeff standing in the middle, unaware that he's become part of the weird, awkward composition. Sheer bliss! It's all so delightfully strange and uniquely realistic at the same time!
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Now look at this (above) more modern example, presumably done by an artist in decline. Once again the gag is about sleeping, but there's no sign that the artist sees sleeping as an outrageous activity. The artist has made his piece with the act of sleeping, it's perfectly normal for him! How sad! And there are other missed opportunities! The fact that it all plays out in a yard, and what a yard is, might have been a kind of visual gag if it had been handled right.
Maybe the problems like this come about because the artist sees the writer as the star, and thinks of himself only as an illustrator at the writer's service. Big mistake! The comic strip is an artist's medium, and in an artist's medium the primary satisfaction should come from the art, not the writing.