Two-inch wide packaging tape works nicely. If this happens, please feel free to ignore the requests. Also, a minimum of 11 pounds and up to a maximum of 66 pounds all going to the same addressee could be placed in one mailbag for a dollar a pound for most countries. Always verify the postage charges, when mailing, since clerks may inadvertently charge the wrong rate. M-Bags are much more cost effective.
Postal regulations prohibit first class letters being mailed in the packages at book rate.
Our ministry allows others to independently mail Bibles to people that desperately need them. Whatever you do will bear eternal results, whether mailing one Bible a year or one bag a week.