wood, end grain

Sub plot: how to stop acetic acid escaping

possible treatments: lime wash, lime wash + charcoal. Ask Morten

Maybe develop impregnated wallpaper, or just alkaline paper.

Hemcrete (hemp core residues + lime + a few other things

clay on or mixed with a support

Wyoming bentonite

Taasinge bentonite

Damolin a/s bentonite

Brick clay (needs a definite source)

Moler, unburned (needs definite source)

waterglass as binder for other stuff.

perlite as binder