Shipping Cassettes Cassette tapes are actually very sturdy by themselves and even more so if they are in cases. You don't need to go overboard packing tapes to ship to us.   If you are just shipping a couple of tapes, a Small Flat Rate Box from the Post Office is perfect. Theye are around $6.50 and that includes the postage. Padded envelopes are fine too.   IMPORTANT: If you are shipping a single cassette or micro cassette, DO NOT use a letter envelope to send us your cassette. Letter envelopes tend to break open and the tape is lost. Use a padded envelope or small box.   If shipping a large amount of cassettes, again a cardboard box is fine, just make sure the box is taped up good.