I think what we've said about intellectual property every other time the topic has come up is basically that if we want to reprint a comic, we have to get the permission of everyone who contributed art or text. Even if it's not the law, which it probably is, it's at least the polite thing to do.
I would probably not buy SC clothing, although if it were kaufman's Cowboy Physics shirt, I could be convinced. I would be more likely to buy other paraphernalia like mugs or, better yet, stickers.
I would prefer that SC merchandise feature full comics, if possible, rather than just characters or a slogan (especially since the slogan would be one we just made up so we could put it on merchandise).
Whatever I do or don't buy, I'll continue to donate.
The idea of syndication raises the question of what periodical would dare risk offending a large portion of its readership by printing the sort of comics most of us write. The other obvious question it raises is, as Scyess originally pointed out, that of copyright.
Of course, there's nothing to stop a group of creative people from banding together, creating their own comic strip, and trying to sell it to an appropriate publisher. But I don't see any way that syndicating Stripcreator content could work.
On the other hand, selling t-shirts is not only not certain to lose money, it's practically guaranteed to make at least a small profit if you do it the way Cafe Press does. You simply figure out how much it'll cost you to make one shirt, then you charge more than that amount for each shirt sold, and you don't manufacture anything that you don't already have an order placed for.
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The what mentioned above is total fiction. Please don't take it seriously!