In two years of sending chips, mainly old illegals, I have had one chip broken. That chip I packaged in a bubble style mailer and had it hand cancelled at the Post Office. Upon receiving the chip back I realized what had happened. I recall hearing the "KA-CHUNK" as the hand cancel was being applied to my package - and breaking the chip into four pieces. I now send chips almost exclusively in the same bubble wrap mailers but take them to the Post Office and request that a meter strip be applied. These envelopes are not put through any cancelling machines and that solved the problem.