Python - Rendering multiple stacked vtkImageData in 2D

Hello,

Right to the point:
I’ve got several vtkImageData stored in an array. I want to take slice from each image and render them on top of each other.
I also need to be able to set different images active and inactive.

When I’m displaying just 1 image I’m using the vtkImageViewer2 and setting the correct slice and the position of the slice as I need it.

Now I need something similar but with several images on top of each other.
I stumbled across the vtkImageStack during my research but it needs a vtkImageSlice as input for the AddImage and I don’t reall know how I would get that from my imageData in the correct way.
I also don’t know how the render the resulting image from the stack into my render window.

TL;DR
Got multiple images and need to render slices from them on top of each other. How?

Thanks for your help.
Greatly appreciated.