I always use plastic for dry and glass for liquid.
Does it really make a difference?

I think glass is better for liquid because to get an accurate measure you are suppose to measure from the bottom of the curve in the liquid which can only be seen if you are using a clear glass measuring cup.

Don't worry folks... I haven't turned domestic on you all. I just remember that from Chemistry classes!

LOL Georgia!

Look HERE

Thanks for the Chemistry Lesson Tree ...

well hey - at least I was right about having a curve in glass measuring cups! So apparently it doesn't matter which you use Clare....plastic or glass...just as long as you know the proper way to read the measurement!

plastic cups are typically for dry measure and glass (pyrex) types with the lips on them are for liquid. You need to look thru the outside of the container to view the level of the liquid, while metal or plastic cups you level off with a straight-edge

usually being a tad off on the measuring wont affect the recipie (unless its a souflee or soemthing picky like that, ive had ONE in my entire cooking life to turn out right), so unless the recipie states that it wont turn out with exact measurements, it dosent really matter which one you use.
i dont even use measuring stuff anymore for most things, i just add the approximate amount, unless its a new recipie that i havent tried before.