Just had an inquire in regards to how I intend to post some posters.

I'm sending them in a registered letter envelope,( $6 charge).

I've also notified them that I can send them in a 3kg bag with full cardboard stiffeners for $10,(close enough for C & S).

I realized afterwards that the last time I tried it wouldn't let me change the postage to a higher amount.

So is there a way that I can add the extra cost?