Varnish has two meanings, and, yes, that's one of them -- but you were
*clearly* using the other meaning when you described varnish as a blend of oil and resin.Yes, some *are* drying oils, as I clearly acknowledged -- but most are not, e.g. corn, soybean, canola, etc.
Then your bike manuals are wrong. Which do you suppose is a better source for the composition of 3-in-1 oil, some bike manual, or the manufacturer of 3-in-1 oil?
Don't just take my word for it -- go to wd40.com and read the MSDS for yourself. Go to a hardware store and read the label on the can. 3-in-1 oil is a petroleum oil. It is NOT vegetable-based.