One tiny picture square. Each sheet prints two of its four spots. Slide B onto A: ink on either sheet blocks light.
Two separate sheets. Slide them together to see what the ink does.
Sheet A picks one of six patterns. For a light picture square, B copies it. For a dark square, B flips it. Either sheet alone still looks half inked.
Practice on pairs that are not part of the real message. Compare A with B: same stacks to gray; opposite stacks to black. The result lives in their relationship.
A fresh pair: two fixed 5×5 sheets made from one badge. Every tiny block is still half ink. Step through the pairs—but do not stack them yet.
Same pair → gray · opposite pair → black
One fixed pair. One hidden badge. No sheet moves before your choice.
When the two fresh 5×5 sheets from the last page stack, which badge appears?
Stack one row at a time. Watch matching pairs stay gray and opposite pairs turn black.
