Longbox editions of Prince's CDs have become rare and highly expensive collectors items.

His first 14 studio albums were released on the long-forgotten format, and unopened editions can fetch $999 and up on eBay.

The longbox was a 12-inch-tall, 5 3/4-inch-wide cardboard box designed to help record stores transition easily from selling vinyl records to selling compact discs. The jewel boxes that hold compact discs are less than five inches tall, and would not be easily visible if placed in a bin designed to hold albums. Two longboxes side by side, however, perfectly occupy the space created for a vinyl record.

Retailers also liked the longboxes because they made it harder to steal the otherwise nearly pocket-sized compact discs. But the environmental cost of using that much paper on packaging that most consumers would immediately throw away led to the packaging format's abandonment in 1993.

As with most artists, the longbox artwork for Prince's early albums is mostly just blown up and cropped versions of the original album art. His 1980 project, Dirty Mind, was the first to include a major deviation, skipping the cover photo of Prince and focusing exclusively on the bed spring background of the original design.

But 1985's Around the World in a Day didn't have a throw-away box, instead arriving in a tri-folded longbox-shaped package. Six years later, 1991's Diamonds and Pearls was packaged in a longbox with a cut-out panel, so the holographic sticker on the CD cover was immediately visible.

You can see front and back photos of 17 different Prince longboxes below. We've also included photos of the three deluxe edition CD packages released during his lifetime, for the Batman, Love Symbol and Crystal Ball albums.