I am looking around for a vintage metal measuring cup and I saw a few that has ONE cup capacity and the sides of the cup has lines and measures in 4ths. I can see using that cup for dry ingredients but since I am camping and going to CW reenactments, I do not want to carry GLASS measuring cups for liquids. In order to use the metal measuring cup and I need to pour liquids in it, how much DIFFERENCE would I need to make a correct measure of liquids in the cup? I am guessing about a TB more into liquid measurement. Still shopping around!