There are exceptions of course. It's certainly possible that someone bought a shirt online and wants to share it here and link to a legit store. But be discrete. 99% of the time, a "source" linked is a scam website that will provide low quality prints, or in worse case not deliver anything or even use a phishing paying page.
Why shouldn't I buy these shirts?
For a few reasons:
The art that’s printed on these is STOLEN art. Sometimes the artist sells prints themselves (i.e. Redbubble.com) and these guy sell them illegally and the original artist does NOT get any money from these sales.
Because it’s stolen art, they don’t have the original image files, which leads to a low-quality print. In some cases, there’s even still a watermark visible on the product page
There’s no guarantee that you will even receive the shirt
Some sites even use fake pay-pages (i.e. phising Paypal) to steal your login credentials or creditcard info.
Various of these sites have abuse reports registered.
Dozens of theft-reports can be found online when searching on their phone-number (855-999-7840)
If you mail their support e-mail address, you will get an “Undelivered” notification, indicating the the e-mail does not exist
How can I recognize these scams?
These art scammers work in a very recognizable way:
They post a picture on a Reddit fandom. Titles like “Got this in the mail today”, or “I made this S H I R T”.
The post from OP itself does not link to any other store/shop
The thread begins to fill with various comments including asking where to get the print. These can come from legitimate users and some from alt-accounts of the scammer(s)
A comment reply appears linking to the spam shop/store (e.g. “In case anyone still want this”). This can be from the OP or another fake alt-account
The link is usually an URL-shorter or leads elsewhere such as their own user-profile, twitter account which then has a link to the store.
99% of the time the print shop is a website that’s created with the platform GearLaunch (Seen by the powered by GearLaunch on the bottom of the site). They create different sites on new names every time to stay anonymous, but other than the logo, the websites all look exactly the same. They always use the same phone-number for the last 2 years (855-999-7840)
Any comments that warn about scam are downvoted by these scammers to get these comments hidden