Artists love the look of a deckle edge. Hand made papers can be made with deckled edges on all four sides, but mould made papers can only be made with two true deckle edges (see definition below). Although many fine art ink jet papers are mould made (the closest machine process to hand made), the final ink jet receptive coating process eliminates the manufacturer's ability to retain or offer a true deckled edge on his finished product.
Paper Glossary: "Deckle Edge": The feathery edge which is the result of the natural run-off of wet pulp when making handmade and mould made paper, or the result of sheets being torn when wet. The edge is simulated in machine made papers by cutting them with a stream of water when still wet.
Artists often try to create an artificial deckle edge by hand tearing the edges of the paper, but this can be very hit and miss, often resulting in a ruined print. Using a steel ruler to guide one's tearing or ripping is better, but often the edges produced have little "character" and are too uniform or straight with some papers.
Digital artists have also tried to put in the look of a torn or deckled edge, by artificially painting the edges with various filters or Photoshop techniques:
Deckled Edges in Photoshop
Torn Paper technique
These digital effects are quite impressive and realistic. However, these digital methods pale in the "perceived value" customers give to an actual torn or deckle edge, because it appears to be "hand made" by the artist. But until the invention of the Dual Edge Ripper there was never a fast and easy way of producing a consistently good torn or deckled edge.