Just an idea if you're going to continue to make Eco Star and DX plastic. Maybe make a little stamp to put on the front that says "Eco" or even a ink stamp on the bottom like the old Roc stamp. It would be much easier for retailers and buyers to discern this from the normal Star plastic. I think it should be visible more than just the 'E' sharpie on the bottom. Just my 2 cents.
That's a good idea. We are currently developing an Echo logo that we can make stickers out of for that purpose.