need help: Bulk adding images to variants

I run a poster shop.
Recently I closed a deal with a frame shop which means I can now offer framed posters. 13 frames for each poster. I have around 200 posters and each poster comes in 4 different sizes.
Summary: 200 posters, 4 sizes, 13 frames for each.
Each poster has 64 variations (pictures needed to be added) because of the sizes and frames.
I have set up the variable products already WITHOUT IMAGES (in total around 12.000 products with variations)
If I am to add every variation image manually it will take me aprrox. 45 hours from my calculations.
Is there an easier way, maybe with csv - or a plugin, that makes it possible for me to add each frame as PNG. over the poster IMG via attributes.

The alternative is that I do it manually around 12.000 times which will be very time consuming.

I really hope someone has a solution or suggestion to my problem.