So we have an Etsy seed shop and the paper envelopes just don't offer enough protection. So I was wrapping the seed packs in a bubble mailer piece. And then shipping. Well some were sent back for being to big. So I bought 100 4x7 bubble mailers. I CANNOT FIND A CONSISTENT ANSWER ON HOW MUCH POSTAGE TO APPLY WHEN SENDING UNDER AN OUNCE PACKAGES. Does anyone know???