Sandable Flexiable Skin for Craftfoam

So while making Azula last year I created something, I had not seen really anywhere else at the time. And it's really simple. And it does like ten things at once. So what does it do? Here's the list:
-Seals craftfoam in 2-3 coats min.
-creates a sandable surface
-levels inconsistent areas and hides seams
-can be used to prime base coat
-remains flexible (for medium to minor range of motion)

What is it made of?
-1 part acyrillic gesso (perferably one that reads flexiable but its not nessary)
-1 part mod podge
-resealable jar (for storage)
Optional:
-Elmer's glue (thinning agent)
-tacky glue (sticking/thickening agent)
-acyclic paint your choice of primer color

And well there it is!
So on Azula I used it all around my edges on my armor. I am obsessive about making seams disappear whether it be in craft foam or fabric. Here's an example, anything gold or brick colored I used the flexiskin.
Can you see the seams?

In this derp photo you are able to see a few because of the strong uneven lighting.

My armor edges remained flexible to a certain point obviously, but still flexible enough to move around freely without damage. Also the neater the seam the better it disappears. 

Pro Tip! 

Remember to add any where from 50 to 10 percent mod podge or any other pva glue to your regular paint for added flexibility and brush stroke less paint.