A great Refina RMR200 roller pan mixer crushing pre-slaked quicklime (from 300 year old lime quarry Cumbria called Shapp) mixed with Cardewmires river bed sand in a volume ratio 4:1. The roller pan crushing method produces a superior plaster to the non compressive forced action Baron type mixer. The crushed lime mixture has a clay consistency meaning it is difficult to apply to a wall (hammering by hands with rubber gloves is eff3vtive) then flattening with a narrow midget trowel to generate higher spread pressure. Cracks do not occur if you are car3ful adding just enough water to make plaster pliable.No artificial plastic fibres, nor horse hair, nor rope strands, need to be added. The Cardewmires sand has a size distribution that helps r3duce cracking; a 4:1 ratio is prefeer3d as it is easier and cheaper to spread than a 3:1 quick lime to sand mixture. After trowel onto wall, wall is sprayed with water and compressed with bare steel trowel to remove any cracks, that way dried wall plaster becomes crack free and only one coat is needed (direct onto pre wetted bricks) thus saving cost of materials and labour. The achiev3d beautiful wall contracts methodology taught in mainstream media. A white silica sand lime mix can be keyed onto the plaster easily if requir3d by troweling it. However trowling must be done with very light pressure by contrast to avoid cracking the final coating, or interfering with the natural delicate subtle suction forces that must be allowed to bond the top coat onto its bas3 coat.