A spokesperson for the association said evidence it was shown at this year's Drupa fair suggested the recycled material was superior to that of offset newspapers, although it was still investigating.

The ability to recycle the print is achieved by spraying a bonding agent on to the substrate during the printing process that aggregates the pigment particles into larger components.

These particles sit on top of the paper rather than soaking in to the fibres improving print quality, but a side effect of this is that these particles are now the right size so that they could potentially be dispersed using a standard flotation process and the resulting pulp recycled.

HP senior scientist for inkjet R&D and environmental strategy Nils Miller said: "We don't believe that inkjet is inherently not de-inkable; there's no reason why inkjet can't be de-inked by the flotation process.

"We already have preliminary studies that indicate conditions under which inkjet prints could be de-inkable."

Dry toner prints are already easily recycled, but the problem remains for dye-based and other pigment inks because they are water soluble.

"Let's not celebrate inkjet being de-inkable yet," the INGEDE spokesperson said. "We just think this is the way to go."

HP, together with Kodak, InfoPrint Solutions and Océ, have recently formed the Digital Print De-Inking Alliance (DPDA) which will look to push inkjet de-inking further with laboratory and pilot trials.