No image after layer merge

[Mithral Londrecken]

I  to a photo of a foot print made with graphite powder. then in gimp i cropped it to just the foot print. Then I used select color to copy the pixs to layers. I have spent hours hand drawing to remove the pixls grainyness for each layer, making depth map of the foot.  Now when I merge the layers my image outcome is blank.  What am I missing?? have not found help on this in youtube. just want to git this inage through to the 3d process but stuck. 

[rich2005]

Not possible to give any definitive answer with the information provided. I know not getting an expected result is annoying but there will be something in your workflow causing the problem.

If possible post the Gimp xcf file with all the layers
or
A full screenshot showing the layers and tool options docks might provide a clue.

If you still have the Gimp .xcf with all the layers intact, it is always better to use Layer -> New from Visible rather than merging layers.

[zeuspaul]

What happens if you *merge down* the layers one at a time?

[Mithral Londrecken]

I am a noob to all kinds of image editing software, sorry, I just don't know what info is or is not needed to give. But I have a basic download 2.10 gimp then with the select color tool picked the different colors, and hit new layer in place. I did open the original file with layers and turn on the alpha channel. the rest however has me at a disadvantage, as for merge one layer at a time i did try that also. but my preview only shows a solid white back ground. so at a loss, but like any good gamer I have saved offen.

---

I tried again a fresh program load with a simple jpg use the rec select tool and chose make new layer in place. Again my layer merge is blank??? wtf???

[zeuspaul]

What happens if you export to png or jpg? You should get what you see on your screen at zoom 1:1 in the exported file all as one layer.

[rich2005]

Extracting information as to cause is often difficult

Quote:...I did open the original file with layers and turn on the alpha channel. 

If originally you select -> copy -> paste-as-new-layer, then those layers already have transparency. Why the need to add an alpha channel ?

Quote:I tried again a fresh program load with a simple jpg use the rec select tool and chose make new layer in place...

As a note, jpeg images do not support transparency and a Select -> Copy -> Paste-as-new-layer-in place will look exactly as the original image. A Image -> Merge Visible Layers produces the same as the original. 

Back to give a screenshot of your tool settings and layers.

You could try resetting the tools. Edit -> Preferences -> Tool Options then Reset Saved Tool Options to Default Values

or this is the procedure I mentioned earlier
Color selected, copied, pasted as new layers.
New from visible of what I want to see.
Either, copy and paste as a new image or easier click-drag from the layers to the Gimp tool box.
If transparency is not required then Layer -> Transparency -> Remove Alpha Channel and you get the current BG colour.

50 second animation of that https://i.imgur.com/QmVmh8S.mp4

[PixLab]

Why do you merge layers?
You just spend hours on layers as you told us I have spent hours hand drawing to remove the pixls grainyness for each layer, making depth map of the foot.,
...and you merge them...Why?
Please don't tell me it's to export...