In CaCO3 studio in Ravenna, I applied their horizontal to vertical mosaic technique where I start by fixing the frame of wood that will receive the mortar, then applying the mortar in a tilted way ( as shown in the picture) to receive the tiles from a horizontal setting to a vertical one. That was interesting to do !
The mortar was applied in an inclined plane.
Tiles applied horizontally
building up the framed box..
.. and going now vertically..
The end result : a flow of tesserae from horizontal to vertical