I haven’t been using the interfacing because it’s more layers than I want to wear when I have to keep the mask on for 4-5 hours at a time. Plus I think the only interfacing I have at the moment is some ANCIENT iron-on stuff I inherited from my mother. (Who knows what kind of chemicals they might have been using way back then?)
I got some of the brackets and they actually seem to work pretty well, but they habe an odd smell. (Made in China and who knows what chemicals might be in there?)