I could be Wrong M but I believe that no such media is available currently - Rewritable media is single layer only as far as I can ascertain ? sorry For your problems though !- Perhaps you can query Joe Ryan - He seems to be very knowledgeable on all things media and if there is such a critter I think he could tell you for sure !!!! Good Luck
JVC introduced a rewritable DVD-RW DL, but it required not only new drives to write to them, but also new DVD players or DVD firmware to read them. No manufacturer was about to design new firmware for the billions of DVD players on the market, so the new disc never entered the market.
The DVD+R DL drives entered the market before the discs did. When the discs (invented by Mitsubishi/Verbatim) did enter the market, they were different from the ones used to design the original firmware, and most people could not write to them with any measure of success until firmware updates were issued. Other disc manufacturers offered their discs, too, eventually; but the yield in the factories was only about 50% because of the difficulty in manufacturing them, particularly because of bubbles between the layers. Drive manufacturers were not happy with the entire DL effort; and when the DVD-R DL entered the scene, it got feeble support. It gets worse: retailers and customers demanded lower prices for discs that were difficult to make, so Ricoh developed a new production method that avoided throwing away a temporary stamper and reduced contamination between layers. However, this new method made the recording surface appear "upside down" to a DL drive. It worked only for drives that had firmware designed for these new discs, so Ricoh decided to reserve this "inverse stack" method for 8X DVD+R DL discs. Retailers refused to carry both the older 2.4/4X discs and 8X discs, so the majority of 8X DL discs that hit retailers' shelves would not work with DL drives unless they were 8X DL drives that had the IS firmware included. Verbatim has apparently been reluctant to move to the IS method because of a greater fear of failure than of too high prices; and Taiyo Yuden has not introduced their DL discs at all because no drives have firmware for them. TY DL discs would fail, and TY would be accused of terrible quality not because of terrible quality, but because of incompatibility that consumers generally do not understand.
DL remains a mess. And no one should look to Apple to be a leader in optical disc technology when they were last in DVD-R, last in DVD+R, last in DL, last in Blu-ray, last......
