Eco Brooklyn uses a lot of natural coatings on our Brooklyn brownstone walls, among them Milk Paint and clay. Both milk paint and clay are both matte finishes and anyone who has painted using matte paint knows that it scuffs a lot easier than glossy paint.
So when we want a more durable finish we seal the coating. But we don’t want to seal the pores. We still want the coating to breathe. That is the wonderful thing with natural coatings. They slowly absorb and release humidity in the room, helping to keep the room more comfortable. Sealing the surface will reduce this porosity but you get a more durable surface in return.
Sealing clay or milk paint is easy and there are many ways to do it.
Wax is a good one. For example pure carnauba floor wax. Pro applicators use Bioshield Floor Wax a lot on top of the American Clay and lime plasters. We don’t like American Clay because you are paying for the name. We prefer to mix our own clay. But Bioshield Floor Wax is great stuff.
Now that I have started keeping bees I have my own wax. I melt it down and mix it with Citrus Solvent, which is a natural alternative to mineral spirits. You can’t beat the feeling of using home made products! And clients love that extra touch!
If you can find it, Black Soap used to be popular but that comes from Africa and there are local alternatives. You can even use household soap or dish soap since they contain oils that impregnate the wall and harden.
Along the same lines you can use polymerized linseed oil, either alone or mixed with wax. Linseed oil makes a nice hard protective coat.
Another option we have used is wheat paste. We boil up some flour and water to make a milky paste and paint that on the wall. The wheat dries and hardens creating a clear protective coat that still breathes.
We have also used AMF Safecoat as a clear protective coating. They specialize in natural coatings.
The point is that there are many ways to coat a wall. Paint from the hardware store is one way but there are hundreds of other ways and many of them are much more ecological and just as nice, if not a lot nicer.