How do you remove the residue remaining on a Westcott ruler from a UPC label?

Whenever a UPC label leaves an adhesive residue on the surface of an item made of metal or plastic, use "Goo Gone" or a similar commercial product intended for this purpose.

Apply the liquid cleaner to a paper napkin or tissue and rub lightly to prevent scratching.

If this step leaves a slightly oily film on the item, a quick wipe with Windex or rubbing alcohol will take care of it and dry instantly.