In a four-layer PCB, how many signal layers are usually present?

[eelik]

Off-topic post closure

We are trying to keep this forum as useful to KiCad users as possible. This means focusing on KiCad related topics. There exists a continual danger of slipping to the subject of general electronics where people (hobbyists, newcomers) ask for help with basic electronics without any relevance to KiCad. These topics will often be closed without hesitation. Nothing personal is intended, nor does it mean that the question or the topic isn’t useful or interesting. Chances of questions being answered…