For membrane installation, the mortar should be mixed to a fairly fluid consistency, but still be able to hold a notch. Mortar should easily transfer to the membrane fleece. For installing tile, mortar should be fluid enough to be easily spread, but not fall off the trowel when picked up. Trowel notches should maintain shape and mortar should easily transfer to tile. The mortar is generally stiffer when setting tile than when setting membranes.