Here, there is no showing that the travel ban is a material burden on individuals' importation of posters for their own use. As to commercial poster importers, we do not read the district court as having found that travel to Cuba was essential for any such importation (see p. 1231
supra ), for clearly merchants over the long history of trade have often arranged for imports without inspection of the wares at the site of production. Even for importers insisting on such inspection, the ban is not absolute, as importers
may travel to Cuba in search of posters if their travel expenses are paid by Cuban hosts or other non-U.S. persons. See
31 CFR § 515.560(j) (1990). Such an advance is by no means improbable, as Cuban poster manufacturers will have a serious incentive to make the investment, especially in view of Walsh's legal inability to pay his own way. Thus, unless we arbitrarily define the affected class as commercial poster importers who insist on on-site inspection and who are unable to secure Cuban or other non-U.S. support for poster reconnoitering in Cuba, the barrier is by no means absolute. (It would make no sense to so define the class, as doing so would in effect elevate the advantages of on-site inspection into essentials.) Accordingly, we doubt that the travel limits amount to “significant interference” with First Amendment rights, the threshold requirement for intermediate scrutiny.