Hi. There are a few specialised products out there for transferring images onto dark fabrics using sublimation inks. Subli-dark is one of the better known ones.
They are not used in the same way that conventional sublimation transfer papers are though. The image is transferred to a carrier medium and the carrier is then adhered to the garment using the press.
There are no significant advantages over using conventional inkjet transfers, with this method. It is not a 'sublimation' print as such, but just a transfer that uses sublimation ink.
Hope this helps.