A plant can misplace a cd as easy as they can the cue sheet. As someone was saying the other day, the master going to the plant isn't an archive master, it's quite temporary and once transferred to the plant system, it's disposable. Although the virgin disk may be the best solution error wise, the issue of ink is one of longevity. I haven't heard of any disks being affected by deskjet/inkjet or water based magic markers for the short duration that exists between the burn and the plant load-in. Marking the disk may prevent some mistakes at the plant, but they have to eat any cd runs that don't clone the master and aren't real prone to that mistake, methinks. I broker for a few clients, all of the plants have different policies as to labeling of the cd and state it in their requirements and templates catalog. It's not really a decision for the ME to make, but following the individual plant requirement. Most advise against paper labels and accept water based marking. The only real problem is if you have C2's and as long as you test the master after you've marked it, get no C2's, no problem.