Lime paint / anti-mold paint in white

Plant casein is used as a primer on drywall boards for lime and clay plasters, but always in conjunction with a reinforcement (e.g., fiberglass), otherwise cracks could form. By the way, most lime plasters have additives mixed in that are not always as healthy as lime itself. There are very few brands that definitely contain no additives.

I am also currently gathering information and offers in this regard and would welcome an exchange!

If I remember correctly, that is a deep primer and yes, it tends to seal rather than open up.

but doesn't that contradict your intended diffusion openness then? I still don't quite know how to apply the top plaster to my walls...

I have an old building that is not really diffusion-open anyway. So the last millimeter on the wall doesn't really matter. Besides, not all walls are exterior walls. I don't even know if there is such a thing as a diffusion-open deep primer at all?