Here’s the cheapest way I’ve found to send a single yo-yo, that minimizes package weight and size, while still protecting the yo-yo.
This method is indeed cheap but it will NOT include any kind of tracking! This is shipping for cheapskates
who are OK with a bit more risk in the name of being cheap, so if you require tracking, look elsewhere!
What you will need
- cardboard (any used box is fine)
- padded envelope (any used kind is fine, it’s actually preferred)
- packing tape
- small plastic baggie
Yo-yo prep
Take apart the yo-yo into two halves. Remove the axle and bearing. Place the axle and bearing into the small plastic bag.
Cardboard prep
Cut two rectangular pieces of cardboard large enough for the two halves to sit comfortably a bit “apart” from each other, with some border around the top, bottom, and sides. Place the halves on the cardboard with the plastic bag in the middle
If you want to include string (you gotta have some string!), put that in the center. This also helps segregate the halves.
Tape it up
Place the other rectangular piece of cardboard on top. Tape it down SUPER TIGHT so the two halves don’t move. There should be a bit of a pyramid shape from being pressed down very firmly over the two halves. If you shake it, nothing inside should move because the cardboard is strongly holding it down.
Place it in the padded envelope
Place the cardboard assembly inside the padded envelope and cut it to fit, then tape it closed. You want to use a boring generic padded envelope so it doesn’t look like remotely like a gift or anything like that. Generic random mail that won’t get a second thought is exactly the “look” you’re going for here.
I ended up with a package that was 109 grams (3.8 ounces), 9 inches by 5 inches, less than 1 inch “depth”. You could cut it a tad smaller than I did if you want to reduce width and length (and weight) a bit more.
USA shipping cost
First class 
domestic package service for a 4 ounce “padded envelope” is $4.06, so make sure you have at least that much on it, in stamps. Current forever stamp value is $0.55 so that’s 8 stamps = $4.40. I guarantee this will work for domestic USA shipping and it is completely safe in my experience. I have shipped dozens of yo-yos this way without incident. There is risk, yes, but it is tiny.
International shipping cost
Per the official USPS shipping calculator, using Turkey 
as a random international example:
-
a 4 ounce “large rigid / variable thickness envelope” should cost $14.25 to ship via First Class Mail International
-
a 4 ounce “large envelope”, with max dimensions of 15" x 12" with max thickness of 3/4" is only $5.10 to ship via First Class Mail International
I’ve found that if you put ~$8 of postage on this package, it gets reliably delivered internationally – not sure if it’s significantly slower shipping, or what have you, but it works. That said, I would not use less than $8 postage! That’d be 15 forever stamps at their current value which is kinda tough to fit on a package this size… so I suggest getting the higher denomination stamps. First class international stamps are $1.15 in value; 7 of those is about $8 and will cover you.
My theory is that we’re barely squeaking by on the 3/4" thickness requirement and they’re letting it slide. 3/4" is 19 millimeters. I just calipered a ti-vayder and each half is ~19mm wide so… the math just about adds up, minus the cardboard thickness and the padded envelope thickness.
Finally
Address it and add stamps for postage per the above, then drop it in any mailbox, you’re done!
Are you nuts?
Well… yes 
There’s virtually no risk to this (in my opinion of course) when mailing within the USA, other than not having tracking for peace of mind or proof that you actually shipped, if needed. However, I will admit there is definitely more risk when sending internationally. That said – I’ve sent ~7 yo-yos this way to Australia, the UK, Canada, Israel, etc and they all arrived fine.
sometimes, I guess I think of it as an experiment… one way you could reduce risk is to put the full $14.25 on there. But at that point you might as well ship in a box IMO.
