I have the pattern called "Snap Happier" and I find it confusing , they mention using pellon and interfacing and iron on of each interchangably. So I'm not sure what to use. And the instructions for the lining is confusing too. I've had better luck making things up on my own. But I wasn't sure how they did the casing for the tape. Anyone else use this pattern ?

I have the snap happy purse pattern and have made several. The lining folds over to the outside and thats what makes the casing for the ruler on mine. The interfacing irons on to the part of the lining that folds to the front and back.Hope this helps

This one says to cut 2 strips for casing (upper band) and interfacing . and cut lining and interfacing.

to a search , click on search at the top of this page, and type in snap bags,