I was wiping off a lens the other day and had an idea. Why don't they make those lens cloths 18% gray? Would that work, or does a gray card need a certain reflectivity (that a piece of fabric would not have)? Does something like that exist? All the lens cloths I've used have been yellow, blue, or some other color - never gray.
They also sell camera bags and many other things in 18% grey. The problem is that it's rather hard to keep something like that, the proper tone & reflectivity. Even a grey card has to be somewhat protected from getting scratched or messed up.
