When making toast, I usually hold the knife over the toaster to heat it up then cut off slices of butter maybe just under 1mm thick

You sound like the EC specification for making a cup of tea - believe me, it exists -something like"slices .972mm thick" would sit easier in the statute book.

Tell me, and I am with the leave the butter out clan, can anybody not tell that "I can't believe it's not butter" is margarine - I can tell straight off, when Mrs.Boxer uses it and reckon that I could pass any blind test?