From a recent family of tests I contact printed a negative image of a step wedge which fit the whole 21 steps on paper. (An original step wedge wouldn't do this - but a negative step wedge developed Normal would).

I cut chips from the contact print to make a Zone System sticker for my Weston Master II meter last night.

I wanted to include one stop of flare in my Zone System sticker, so I picked the next step above blackest black for my Zone 0 chip.