[mtbopfuyn]

The technique of making concrete was known to the Romans, then "lost" for hundreds of years.

There is also a flesh tone color in stained glass that has been lost. It's like Granny's muffins you remember from your childhood but she took the recipe to her grave and no one has been able to make them since. Things are lost or forgotten every day.

[justshutupandtakeit]

But the real point is that this image was not visible in any detail until seen as a photographic negative. Thus, no one could have painted it since they couldn't see what they were doing.

[KneelBeforeZod]

It's like Granny's muffins you remember from your childhood but she took the recipe to her grave and no one has been able to make them since

goose fat