Not at all if it's to a developed country. I've had no problem with Canada, Spain, Great Britain, Chile, Australia, New Zealand and others. I would NOT ship to any African country or any of the Soviet countries. Be sure to use air for overseas. All that obviously contain something other than paper require a US customs declaration. "Plastic novelty items" seems to work without attracting undue attention. I've also used "poker chips".

I've had Canadians request Global Priority Mail, but not sure why. First Class seems to work fine. Might take a day or two longer.