A friend of mine wants to use her artwork and sell it on one of those sites that sells t-shirts, mugs, etc. but I am not very familiar with them. I want to know what the best options are and who pays out the most in commission.
I heard Teepublic is pretty good. I can't recall what you make per item but I remember them being better than many others out there. Might be worth looking into that one as an option.
I heard good things about RedBubble but I have never used them nor shopped through them personally. I know a few people who have and they do provide quality items. I guess it depends on cost and location.
Teespring and Zazzle are the only ones I know of. I have gotten shirts off of both to support YouTubers and independent creators. They seem to do a good job. The issue is though, I am not sure how much people actually make on those shops.