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?
> ...
![](https://ci5.googleusercontent.com/proxy/ISM9nZJa5RLBCBwQkXr3Xr0dLgFht7mOSpQFH1xCoCVHdOCsFG5UxC6888fxPrjI2uqJ3IR9cmkkEVhRMIYRTg8t0ys_LNE8D_EAUdMgYQVn284OsvVpa33-l5ZnmJw=s0-d-e1-ft#https://www.jlcpcb.com/email/email/getImage/3d2785614c214e96b09ccea774d57cf8)
I'm not really sure what's going on here. In Layer Manager, I have:
![image.png](//image.easyeda.com/pullimage/WJPcOHGSzJOoaCndVkt7qUHBrmcYRDhkpfxQcp6X.png)
<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>
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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?