[andyydao]

This is all a bit confusing but it's starting to makes sense now.

What I actually want the license to be is CC-BY-SA - I think this mean that people shouldn't making money out of the illustrations e.g. putting it on a t-shirt and selling it, but rather using it in their commercial website/app.

Is this correct?

[boogies]

SA is copyleft (https://en.wikipedia.org/wiki/Copyleft, http://www.gnu.org/copyleft/, http://www.gnu.org/philosophy/pragmatic.html).

That just means everyone you share your stuff with must share alike (what SA stands for) anything they choose to publicly publish that they’ve made out of your copylefted work (their derivative works), in the same way you shared it with them (as https://creativecommons.org/licenses/by-nc-sa/3.0/ says: “ShareAlike — If you remix, transform, or build upon the material, you must distribute your contributions under the same license as the original” — in this case CC-BY-SA).

That doesn’t mean they can’t sell it, it just means they can’t claim it as their own and refuse to let any one else make their own derivative works of it under the same terms they made theirs.

(Edits: Formatting and quote)

[quadrangle]

There's no license that lets people use it on a commercial website but not to sell it on a shirt.

The only way to have that situation is to keep it All Rights Reserved and make separate contracts with people for all uses. That would totally undermine your goals.

I think CC-BY-SA is what you want. People aren't likely to sell it on a shirt, and if they do, they still have to give you credit (that's the BY part), like on the shirt itself I'd think even. If you left off the -SA part, people could make new versions and make those versions restricted instead of sharing them under the same terms.