I have spent a lot of time studying the Maya and I can read some Maya
hieroglyphics that are 2,000 years old. Some of the tall, stone stela have fallen
over and have been lying on the ground for centuries. On the side in the
dirt/mud, the glyphs are in excellant condition but the side on top is unreadable.
That is because of the weathering. Therefore, I conclude that storing
archival material in mud is the best preservation plan.
There are a couple of little problems with using stone for writing. One is
that it takes several days, or weeks, to write a sentence and the other is that
each glyph is about 3 inches by 3 inches so the packing density is rather
low. Also, you cannot white-out your mistakes.