Hi James, Your burning software should be able to recognize what type of disks that you are using. Of course, when burning double layer discs you need the 8.7 double layer media. I didn't know that fact when I first started attempting to burn in the DL format. I spent a good few hours screwing up. I use Toast and it has you choose which media you want, either "DVD" or "DVD DL". I only use DL discs on occasion as they are still relatively expensive. I only buy them when they are around a buck apiece. Bill Montreal