Puerto Rico should just have a standardish usps label, at least last time I sent
one. We quit shipping outside of the USA in 2020 when packages were getting lost
everywhere. That said, I'm not up to date on this. However, when shipping
out of the US you would have a CN22 (if I remember right) label. Which takes
the place of your standard usps label. You have to input more information to
get the label, such as itemization of what's in the package, country of origin,
you have to sign and date the label, etc.. No bubble mailers, only boxes. And
base shipping prices starting at maybe $15, compared to a couple ounce package
in the usa costing around $3.50 (4 years ago). Just pointing this out because
you are paying percentages of the order total. You have to take into account
minimum buy vs the greater fees and weight of the packaging. Hopefully someone
with current experience shipping to canada can critique everything I mentioned
here.