CC-BY-SA is not "free for commercial" use. CC-BY would be.
Whether you choose CC-BY or CC-BY-SA is up to you but the title says "free for commercial use" which CC-BY-SA is not or at least not for the use cases shown.
If you really mean the share-alike part, i.e. that when you modify the image then anyone is free to use your derived version under the same terms, and you actually object to that clause, then I'm sorry but that's just stealing the author's free work without sharing whatever small edits you made back.
* incorrect, Non-Commercial is still an available variant of CC also in version 4.0, see u/quadrangle's comment below.
Oh, I thought I remembered them having dropped that because it was hard to define and actually reducing freedoms or something. Perhaps that was the FSF/OSI standpoint instead (though GPL never had it, so idk where this idea came from). I stand corrected about it being "previous" :)
There was a strong advocacy push for dropping NC or at least renaming it CRR (commercial rights reserved) to be clearer. But CC decided that dropping it for v4 would likely just lead to people continuing to use the v3. And if they use NC anyway, better to at least have the updated legal language than the outdated version.
I don't think commercial use is incompatible with an SA license.
Maybe it depends on how you define commercial use but if you define it as "any activity in which you use a product or service for financial gain",
there would be no problem putting one of these images on a product and sell the product and still give the consumers the freedom to use the images under the same license.
Gregg is wrong. Thanks but no thanks Gregg, you are confusing people. CC-BY-SA allows free commercial use. It just means that if someone makes a derivative of the work, they also keep that derivative CC-BY-SA (which is good) rather than locking down the rights. But they can do commercial use without any limitations.
The use cases shown on the page https://www.pixeltrue.com/frontliner-heroes are all derivative works. BY-SA means you can sell the picture but as so as you add text it's now a new derivative work (like every example on the page)
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.
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.
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.
Don't listen to this guy, as far as I can tell the only purpose of wanting the share-alike clause gone (which doesn't prevent commercial usage; it literally says that on the page you linked above) is to take your images and sell them on something like shutterstock.
This is wrong because many uses of the work, like adding it on the front page your your site with some caption, is a derivative work. Putting it on a page by itself or printing on a t-shirt would not be derivative but using it as a logo with text would.
Whether you choose CC-BY or CC-BY-SA is up to you but the title says "free for commercial use" which CC-BY-SA is not or at least not for the use cases shown.