I have been looking for a way to send small seeds protected from crushing in a normal envelope for one stamp. I think I have found it. A coin flip is a thin cardboard covering for protecting collectable coins.I sent one to a member with some mallow seeds in it and it went thru fine. I have not tested how many you could tape side by side and stay under the weight for one stamp. That will depend on the weight of the seeds too. If you would like to try it out we can trade . I can send small seeds to you in coin flips for one stamp and you can send them back with reasonably small seeds in them like a test. I want to see what the limits of seed size are and test them for sprouting to be sure they are not cracked and ruined. We should trade common stuff we have in abundance for this test. Coin flips can be purchased for a few cents each from a coin dealer or on e-bay in quantity. Ric

Here is a link that might be useful: ricjo22's exchange list