Back in the (50s) day, you could (in the UK at least) ask for bacon to be sliced at 'Number 4', or whatever. This then ensured that the bacon was sliced to the thickness you, or your mother, wanted.
I have never really been able to get the various items of charcuterie we buy in the supermarket sliced to any degree of consistency; it's either too thin or too thick a good deal of the time.
Is there any equivalent in France to the old Berkel No. 4 system? I can see the person behind the counter spinning a dial, but would like to be a bit more precise than fin or moyen. Sure, they hold up the first slice as a sample, but will often then add the sample to your purchase, even though it's not the thickness you want. (As everything is sealed up until you get it home, you don't find out until it's too late.) Does anyone know if these slicing machines also have numbers that customers can specify?