> Btw, do you think there is a difference between 25GB single layer and 100GB M-Discs regarding the media robustness and safety of data? As i understand it, th

> Btw, do you think there is a difference between 25GB single layer and 100GB M-Discs regarding the media robustness and safety of data? As i understand it, the 100GB discs add another data layer, and assuming it works like all other optical media, this is achieved by angling the laser at a different angle, so logically a scratch on the physical media will incur read errors on another layer. Apart from physical damage, the media density is higher. I would assume that the 25GB discs have a longer lifetime than the 100GB ones, but I have no illusions that either of them will last a millennia. If the media is still readable 1000 years from now, let’s hope they still make optical drives to read them :-) I’ll be happy if they last 10-20 years, and considering some of the early CD ROM disc that were burned are still readable despite using dye (which degrades) I’d say there’s a good chance of that either size will survive just fine. I store mine in jewel cases, in a dark closet at room temperature. The worst enemies are temperature, light and humidity.