As Amazon and other shippers pride themselves on sending items that use substantially less material, I find those mailers a little risky for me to re-use. The blue plastic Amazon padded envelopes were a wonderful re-use material. I have received insulators from several collectors with bubble wrap that was used too many times. Heavy insulators will tend to flatten bubble wrap and to a lesser degree cardboard. I re-use with care, and I don't reuse everything. Point of view: I don't think it is right to use the USPS bubble mailers as a substitute for bubble wrap inside a package; so I don't.