What's this process called?
 

What is it called when you take a panel (or something similar) and cut it then border each block with sashing or attic windows? The result is the same picture, but like looking through a window or bars.

I don't think there is a name for that, specifically. I think you are just making a quilt top. :thumbup:

Attic windows would describe it the best.

i've always known it as attic windows

It sounds like diptic or something. Just can't remember...