I'll like to see those pictures!
Hope you have taken pictures of the whole stage from start to finish.
I have started using grout, as you will see in picture in the link that I have added.
It looks allot better and you got more design capability from it.
I still like to paint my stuff as I feel its saver for the Tarantulas and it just seals it off to prevent water from damaging it.
Just check if you going to be using bonding liquid that it’s not toxic for your Spiders or
Bearded dragons or leaves toxic smell in your cages.
But I don’t think it will do anything .
DIY back drops