ORIGINAL: zetor
I just finished off a bottle of epoxy and I had hardener left over (about 2 teaspoons). I never payed too much attention to the tic marks on the side of the bottle because it takes so long to run down the sides and with 5 min epoxy you need to hurry if you want to get it wiped off the covering.
The tic marks tend to be a very inaccurate method of measuring. I mix my epoxy in 1 ounce dosage cups to be sure of the ratios. The cups are disposable, cheap and readily available at your local hobby shop or drugstore. (they might be a little cheaper at the drugstore)