Hi kosko,

If you can get the seeds into a bigger envelope (either business sized or regular sized) to bring the thickness of it down, you will be able to send it cheaper. If the envelope can not fit through that slot that they use at the Post Office, then the postage starts going up sky high.

Good Luck

I lay the seedpacks evenly on a piece of cereal-box card, cut to fit the bubble envelope. Then, I wrap it with "press and seal" wrap. The packs don't shift, and they fit the template. It's the 'bulgey' packs they don't like.
I used this method for a round robin, and we didn't have to pay higher postage.

Wendy

The bubble envelope must be a maximum of 2cm thick and 38 cm Long x 27 cm Wide to be classified as an oversized envelope delivered within Canada.

Non-Standard and oversize envelopes including bubble envelopes

up to 100g is $1.10
Between 100g up to 200g is $1.86
200g up to 500g is $2.55

After 500g it's a parcel.

Most seeds can be mailed in a #0 or #1 size bubble envelope under 50g for $1.10

Here is a link that might be useful: canada post

jimmyjojo nailed the official version.

However - one can mail padded enveloped that exceed Canada Post's stated dimensions. Usually... If you do it a certain way... And you have to accept that it may not go through - that has only happened to me once though. (Dimensions only - you cannot exceed the weight. You have to be a stickler for weight.)

What you don't do is hand it to a postal clerk. Never, ever, ever! They'll apply the official standards 100% 0f the time (it's their job, after all). If you are unsure about the weight of your padded mailer, ask them to weigh it for you only - do not ask them to mail it. Add postage appropriate to the weight ($1.10 if it is under 100g, or $1.86 if it is between 100 and 200g), and place it in a mail box (the big red sort) outside of the post office - preferably one on a busy street corner.

Ninety nine times out of one hundred, this will go through, but because it is not officially correct, you may have it returned postage due. As I said, this has happened to me only once, and I do it all the time.

BP

Kosko, surely that clerk made an error. Yesterday I mailed a box about 12 X 18 inches and about 4 inches high. It went Expresspost, insured for $55 , requiring signing for receipt and that cost me $12.00. Try another Post Office.