I used the "one click" method in EasyEDA Pro to order a PCB + Assembly from from JLCPCB. Here is my project: [https://oshwlab.com/carlk3/rp2040-sd-card-dev](https://oshwlab.com/carlk3/rp2040-sd-card-dev). I got a question from Susie at JLCPCB: > As shown below, it seems that the inner layers are positive film pattern. > > Is that Ok to proceed per file directly? > ...  I'm not really sure what's going on here. In Layer Manager, I have:  <span class="colour" style="color:rgb(34, 34, 34)">I read about the "Negative film effect" in the </span>[EasyEDA Pro Tutorial](https://prodocs.easyeda.com/en/pcb/tools-layer-manager/index.html)<span class="colour" style="color:rgb(34, 34, 34)">, but it's not clear to me how to switch it from positive to negative. My intent is to have (mostly) solid Power and Ground inner planes.</span><br> <br> In general, is there any real difference between a "Plane" type inner layer and a "Signal" type with a copper pour? One is negative film pattern and the other is positive? Is the end result the same? I'm not trying to do anything tricky or unusual here. I just want a normal 4-layer board with power and ground on the inner layers. It sounds catastrophic to accidently swap positive and negative film patterns! How should I proceed?