The first screen you see when Pad2Pad is opened shows you some basic properties of the board you are about to draw.
Figure 9.1
As you can see, the software in its default configuration chooses a 2 layer board at 4 inch by 3 inch. The solder mask is enabled and the silk screen is on the top side. I highly recommend leaving the solder mask and silk screen as they are unless you need silk screening on the bottom layer.
The solder mask enables surface mount components to be soldered more easily without bridging pads which causes shorts and other nasty side effects. The silk screen is a printed version of the board you draw in the software. That means all component names, descriptions, and identifying marks you draw on the board using the silk screen layer (more on that later) will be printed on whatever side you enable silk screen printing on the boards you order.
For our project, two layers will be plenty sufficient. The final size will be considerably smaller than the default 4 X 3 setting, but we can change that after we have the components installed on the board. At that point, we will know more about the size we require.
