Sorry, obviously I have not made myself clear. Let me elaborate
further.
I tend to buy a ton or two of freshly harvested grapes and use them for
wine making. These get delivered to me in a small truck. However, I
dont always trust the growers/sellers as to which variety they claim
their grapes are. Obviously they want to get rid of their grapes ASAP
and if they claim it is franc or sauvignon, I just have to trust what
they say. As I am not a grower I have little vineyard experience. In
the books (photos) and in reality they both look very similar to me.
Hence, marking the boxes with "cabernet" or "franc" does not solve my
problem!