What I most admired about the aesthetic was its boundless energy and unpredictability, and the way it let rappers be upfront and extroverted about their desires. The covers also perfectly complemented the music within — onslaughts of bold and abrasive sonic experimentation. Whether for canonical artists (Snoop Dogg, Lil Wayne) or for radically obscure ones, Pen & Pixel covers represented a sort of promise; not a guarantee of quality, exactly, but one of imaginative humor and deliberate, playful surrealism.

The firm was founded by two brothers, Aaron and Shawn Brauch. Aaron had an M.B.A. from Cornell and was a proud lifetime member of Mensa. Shawn was a scuba-­diving enthusiast with multiple design degrees. Originally employed by the seminal Texas hip-hop label Rap-A-Lot, the brothers soon found themselves inundated with outside requests. They struck out on their own in 1992, their operation consisting of a computer and a dining-­room table, and by 1998 they were reporting gross annual profits of $3.7 million. They started their own TV show and, as Shawn told The Los Angeles Times that year, planned a book of Pen & Pixel artwork, “including a magnifying glass, to see all the detail.”

And what detail! Rappers delved into their own psyches and dreamed up scenarios in which they tamed tigers, leveled skyscrapers with laser vision, gaped at alligators or reigned over ruined worlds engulfed in flames. The results may have started out as an affront to mainstream taste, but by the turn of the century they were practically a primary expression of it. The firm decorated the covers of 750 million albums sold, including 12 platinum and 38 gold records. It might be more accurate to say that the firm burrowed into the id of mainstream taste, stripping it for parts in a manic cut-and-paste frenzy. Its success was accompanied by the usual hand-­wringing: The Brauchs were dismissed as tasteless and grossly materialistic by people who probably danced at their weddings to Barrett Strong’s “Money (That’s What I Want).”

The Brauch brothers have cited Napster and Sept. 11 as the twin harbingers of Pen & Pixel’s demise: Fears of file-­sharing and terrorism alike apparently rendered long-­distance flights to Houston to spend large amounts on artwork (which listeners may or may not even see) a hugely optional luxury. In the company’s wake, rap-­album art has in large part degenerated into a kind of solemn professionalism, a zone overcrowded with nostalgia and self-­serious monochromatic portraits. There’s less room today for the truly unexpected juxtaposition — no pineapples, pet cheetahs or convertibles riding waves like surfboards. What I miss most about these covers is their tendency to transform real-life injustice into a luminous and liberating absurdism; the world of Pen & Pixel was limited only by artists’ imaginations. They shared cigars with grizzly bears, recast themselves as Rambo-­like war heroes and constructed still lifes out of Rolex watches and bottles of Moët & Chandon. And we were all allowed to take part, if only from a distance.