That's my experience as well. Generally I will reinforce even the padded envelopes at the flap but with the cardboard ones, often I reinforce every edge and spend way too much time doing that and I'm still not comfortable if I think they are overstuffed.
Originally Posted by
moonrise
Yeah, those cardboard flat rate envelopes have given me a lot of trouble. I don't know if it's the Georgia heat, the humidity, or what, but the flaps always seem to pop open. The adhesive they use just doesn't hold up. On top of that, the cardboard tears easily... Anyway, I just order the padded mailers now. They're much more durable and the adhesive stays stuck. And they seem to hold a lot more stuff.
