Be honest about the contents. The guys and gals at customs seem to resent being deliberately misled for some reason.
If it's switchblade, bali or pushdagger, don't send it. It's prohibited.
If it's deliberately concealed to start with ie cane sword, belt buckle knife, don't send it.
If it's D guard or holes in the handle ( like a karambit) they like to seize it as "brass knucks". Kind of a stretch, but they do.
Lastly 'gravity' knives are prohibited. One of the gorilas at customs apparently even managed to 'flick' open a queen cutlery slipjoint - and seized it. (only one like that I've heard of), but if it's a folder, I'd suggest tightening the pivot so it WONT flick.
Most of us up here are used to dealing with customs and know full well what may be a problem. Remind your customer that his country's import restrictions are his matter - not yours and ask how would he like it shipped (at his risk). By the way, he will likely pay taxes on the HIGHER of
- The declared value
- The insured value
- The value shown on an enclosed invoice
- (rarely) An assigned value if they don't accept the above)
The matter has been discussed at length in the Canadian community forum, but 'caveat emptor', there is both good and bad advice in there.
Thanks for asking
Rob!