On Thu, Apr 14, 2016 at 11:47 AM, RussellMc <apptechnz@gmail.com> wrote:

> Properly done, and that applies to paper & vellum too, concrete does OKis=
h.
> ...
> Concrete weathers badly in many cases. Many grave stones in 18xx cemeteri=
es
> (and older) are unreadable.
>

If you want information to last a long time in all weathers, then it seems
trenches filled with chalk works well
https://en.wikipedia.org/wiki/Uffington_White_Horse

Though given the right storage conditions, paint on walls also seems to
last a long time - one example of appropriate storage being inside caves,

Chris
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