Felted lunch bag

I’m doing a Felted lunch bag for my Ravelmpics Project and I want to do a modification. Instead of using a button I want to use a strap to hold the flap down. Should I attach it before or after I felt them?

TIA :muah:

I think it would depend on what you are making the strap out of. If it also would need to be felted, make it before and felt but I wouldn’t attach it until after everything is felted. That way you’ll be sure it is the length that you want.