Sausage bags are all you need
Those slingshot satchels from back in the day were ahead of their time in defining kiting as gay as it has become.... or maybe as gay as its always been
Switch bag.
I can easily put 2 kites in it, including an 18m.
It has a zipper all around to expand it.
What more could you possibly want ?
I use these:
www.ikea.com/au/en/p/frakta-trunk-for-trolley-blue-90161989/
Cheaper than the $6 version above and comes with rucksack straps. Cheap enough to throw away when the zips corrode. Get a marker pen and scribble what size kite is in there and you are set to go.
Edit: 2 kites will squeeze in if rolled properly. One kite will fit with the most ham-fisted of pack downs before the rain squall hits
Back to the question - flannelette bags aside!!
I have an Ozone travel bag which is apparently designed for TT 2 boards (fins off ) and then another section for kites - I can squeeze 3 in with a harness and a pump but its getting seriously heavy at that point. Its a carry bag ( has a shoulder strap ) and doesnt have wheels - Its already heavy enough !! Id have to say Im pretty impressed with the bag - after quite a few trips the bag and my gear are still in good condition . After a bit of travel Id love the ease of wheels on the bag but they add so much dead weight - Im strong enough to get by bag to the checkout and then off the over size baggage area so Im still living my ozone dream !!
I dont ride a TT anymore so use the Ozone bag for my kites and clothes - and have a seperate bag for my surfboard - I usually come in at around 32 KG with both bags. Travelling with 3 kites at 4 kg each plus all the other stuff seems to add up faster than you think !! Hapy Travels !!
I did a camping trip to Lizard Island where weight was critical, also had to carry gear quite a long way I took two kites and two pillowcases, worked a treat. Just in case you're wondering I transported the kites in the pillow cases in a backpack and used them as pillow cases whilst camping.