I recently bought a GSI Cascadian mug and one thing it's missing is measurement graduations. BPL has a review of the cup which apparently does have measurement markings on it. Does anybody have any ideas as to how to mark the inside of the mug with 1/2 cup, 1 cup, etc? It's not quite translucent enough to see the liquid level from the outside so I can't mark the outside. It's made out of polypropylene so a regular magic marker probably won't stick and might be toxic anyways. I was thinking of melting lines in it with a soldering iron or touching it with a dremel grinding wheel to carve a slight groove. Neither of these would be a good contrast. Thoughts?
