I find out with my new 25-spindle of DVD-R 16x (MID code TYG03) that blank DVD's stick a bit ont the fingers when yo touch them on the edge and that this pack of 25 smells stronger that my oldier spindles.
Maybe it is because these 16x rated ones have been manufactured (in Japan) more recently than my TYG02 and TYG01.
For a single DVD in a jewel box it is harder to tell ...
I dont think that these dogs are able to smell the different dyes (cyanine, Azo, ...) and distinguish blanks or burned discs from pressed ones.
This dye is supposed to be well sealed inside and protected against the penetration of oxygen.
Either the polycarbonate but more probably
the glue used for bonding
all DVD's (pressed and burned ones) must have a special smell.
If you read the original article:
http://www.fact-uk.org.uk/site/latest_news/index.htm « They were amazingly successful at identifying packages containing DVD’s,
which were opened and checked by HM Customs’ representatives.
While all were legitimate shipments on the day . . . . »
it is said that the customs have to do a "hand job" on every single parcel in order to check for illegal copies after a dog sniffed out a parcel containing DVD's.
I think that the larger the quantity of DVD's is in a parcel the more efficient the dogs are,
as I cannot see these dogs sniffing out every
single pressed DVD
sealed in a jewel box
with the transparent paper
around.
From this news I learned at least that there is a (little) way to tell if a spindle of blanks
is still fresh (because there is no date for conservation on blank DVD's ...)