Paper: It’s a Question of Brightness

For starters, paper that has achieved its brightness through the use of FWAs can’t be measured in a meaningful way for that brightness, because different brightness instruments currently in use (e.g., Datacolor Elrepho, Technidyne ColorTouch) read FWAs differently. In other words, the same sheet of paper can have different brightness measurements depending on the equipment used to evaluate it. (This is one reason some foreign sheets have higher reported brightness levels than U.S.-made sheets.)