How to overlay many textures?

I have the problem that I want to overlay many textures. Some are at the same place of the material and when I lerp them again and again the fist textures are not seen. I use different alpha values so that they should shine through the other overlayed textures.

You will need to make the goal clearer to get much help.

Lerp combines values with an alpha “weight” but even if you used 0.001 you would eventually replace the original image completely.