I think outside the box

Fear me....I have found, cut and sewn the ideal material for pattern pouches to go with my WIP bags:

It takes an A4 piece of paper folded in 4 and shows one side completely, no edges.


Without the pattern in:


Now I need to decide how to fasten it to the main bag......maybe a popper on the outside of the main bag and otherwise it goes loose in the main bag......?