<p>In slicer G-code is it possible to set the probe Z offset for the first layer only?</p>
<p>For my stock E3 plate I find -4.125 mm best however for glass I need to go to -4.175 mm for the first layer to get better adhesion. So it's a manual process every time. Any way to tell the slicer do the first layer at -4.175 mm and next ones at -4.125 mm?</p>

I don't understand the reasoning behind a first layer having a different offset from the following layers, but, You can manually add a re-definition of the current height after the first layer, suppose your first layer is 0.2 mm, you just need to tell the printer to move to a slightly higher next layer to redefine this as a different Z-offset.
From a G-code file find the start of the second layer:
```
G0 F600 X141.541 Y109.467 Z0.37
```
Modify this to:
```
G0 F600 X141.541 Y109.467 Z0.42
```
Now insert the following command:
```
G92 X0.37
```
Now it is like you have changed the Z-offset.
The reason for not using
```
M206
```
is that is applied onto current offsets, if you accidentally save setting to memory after printing, it stores this offset. You can use
```
M206
```
, but use it carefully. A re-definition of the Z level is never stored, the next
```
G28
```
erases the effect, so does repowering the motors.