If ever you had a single question about the felt magic Jim Henson managed to create, chances are Brian Jay Jones’ sweeping new biography of the puppeteer will answer it.

Wondered why Miss Piggy is the way she is? Consider that her father was killed in a tractor accident, at least in the elaborate character back story created by the Muppets’ masters.

Thought Kermit was always synonymous with frog? Fact is, he had not taken on an amphibious identity in initial appearances, and was not green but the milky blue of an old coat of Henson’s mother.

Curious about the Muppets’ late-night engagements? Bet you didn’t know they once shared a Las Vegas stage with Nancy Sinatra and made regular appearances on “Saturday Night Live.”

Jones offers a meticulously researched tome chock-full of gems about the Muppets and the most thorough portrait of their creator ever crafted. Henson’s story, from his birth in the Mississippi Delta, to his first forays into puppetry as a teenager, to his sudden death in 1990 at the age of 53, is documented in depth.

We’re taken along to the creation of iconic characters, the birth of “Sesame Street,” the strain in Henson’s marriage, friction with revered children’s authors Roald Dahl and Maurice Sendak, and unending merger talks with Disney. We learn Henson’s first choice to cast in the central goblin king character of “Labyrinth” was Sting, not David Bowie, who he was swayed to choose by his children. We’re told of Henson collapsing in fits of laughter on the set of “The Muppet Show,” of him spending hours underwater to film the “Rainbow Connection” scene of “The Muppet Movie,” and how the puppets were so real they could be disarming to crew members.

It is, in a word, exhaustive, and at times, exhausting.

At its low points, the book drags, reading like an old datebook of Henson’s, chronicling every Christmas, every vacation, every minor project, every critic’s review. But at its best, it gives a glimpse of the silliness on Muppet sets, of Henson’s drive and his soft-spoken genius that in such a short life managed to create so much.

It is a better world with the Muppets. And we are better off with this careful account of their master.