TeDaDeS
Forum Addict!
It's not unusual to also have multilayer boards with all via's going all the way through, it's cheaper to produce that way.Looking at my prototype from 2016, I can find nothing on it to indicate it's more than a 2 layer board. I can find no flood fill ground plane for example, other than parts visible on the underside of the board, and have as yet found no vias that don't go all the way through the board (although being under the white paint on the topside can sometimes be hard to spot).