[QUOTE=Musicat]
I think the commercial ones are pressed with the polycarbinate layer first, then the reflective layer (which would be deposited on the back side of the data-reading area), then the protective layer, then a label or label layer.
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This is exactly right.
[QUOTE=Musicat]
But blanks for burning could be made differently – I don’t know, but this could affect the thickness or composition of some layers.
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From what I can tell, the construction is similar, except that instead of pressing a pattern of pits into the polycarbonate disk, a dye layer us deposited. The remaining steps are identical to pressed CDs.
[QUOTE=Musicat]
But your post mentioned the construction of DVDs as different.
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Right. And if you look at the edge of a DVD (magnification helps here), you can see the data layer sandwiched in the middle of the disk. It’s actually two polycarbonate disks cemented together with the pressed data/dye layer (or layers, in the case of dual-layer DVDs) and the deposited aluminum reflective layer between them.
Could be scare tactics to sell higher priced pens, true. But it’s worth the extra $$ to me for the peace of mind. I’d rather eliminate the risk when it comes to my image backups. Imagine calling a couple who’s bridals you shot saying “umm, the disk is unreadable, sorry…” - had to do that once - now THAT’S a hard phonecall to make.
[QUOTE=Q.E.D.]
I find that very difficult to believe. The solvents used in standard Sharpie markers are all highly volatile (see the Sharpie marker MSDS). I can see CDs possibly being affected, since the optical layer is only protected by a thin lacquer coating on the label side, but DVDs have the optical layer sandwiched between two half-thickness polycarbonate discs. No way is the residue from a sharpie going to eat through that enough to cause any damage, even if what you say is true.
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[QUOTE=Daylon]
Could be scare tactics to sell higher priced pens, true. But it’s worth the extra $$ to me for the peace of mind. I’d rather eliminate the risk when it comes to my image backups. Imagine calling a couple who’s bridals you shot saying “umm, the disk is unreadable, sorry…” - had to do that once - now THAT’S a hard phonecall to make.
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Sort of like Pascal’s Wager, eh?
