In order to place the tile pieces onto the base you are working on, you can either spread the mortar or adhesive all over the area you are working on, or you can “butter” the back of each individual piece. Buttering has been my preferred method for most of the birdbath work I have done.
You can see a bit about the consistency of the mortar. It will not drip off in this small amount. It is thick enough to stick to the piece. However, a large dollop of the mortar would not stick to the knife against gravity.
