Generally speaking, does FDA approve individual inks or do they
have a list of ingredients approved for use in inks or coatings that
will have contact with food? From my experience with the can
manufacturing industry, I think it is the latter so "new" inks can be
designed and formulated without lengthy FDA approvals as long as
they use only previously approved ingredients. If the new ink uses
ingredients not already on the approved list, then the process is
longer and more complicated.