copyright. It is surprisingly strict when it comes to origami. The final model (Yes even if you've folded it) is copyrighted. The folding sequence is copyrighted. The right to teach it to others is also copyrighted.
I am not surprised.
Origami is a "manufacturing process" and should be patented instead although the U. S patent or other patent offices might not agree with me.
As a patented process, the inventor (yes, it is an invention) should be paid a royalty.
===============
after failing at posting origami instructions on tumblr and instructibles.
Instructibles especially was a complete failure. Completely incompatible with my phone. I couldn't even resize a picture.
You did not fail. The app or platform did. You just gave up trying.
==============
From here I met @cryptocariad and @marblely and now @marblely is holding a weekly competition called Thursday Favourites.
I'll continue to support you if you would continue to host a contest.
Hosting a contest is a great learning experience. It's somewhat like hosting a real party or like herding cats as it is difficult to know what motivates people to join or not.
It's always difficult in the beginning.