toby doesn’t want us selling unofficial undertale merch. art commissions are fine, but things like buttons, t-shirts, posters, etc are not.
please respect toby’s wishes. please don’t sell unofficial undertale merchandise. please don’t be that person.
source: toby’s twitter has multiple tweets about it as seen above
If you really want to support Undertale/ Toby Fox, PLEASE buy the official merch from fangamer.
actually as of february 2016, toby fox has changed his policy on selling fanworks as seen here, the tl:dr being merch like charms, stickers, prints, handmade items and fanbooks are okay to sell, but mass-produced items (like machine-made tshirts or plushies), things that break the UNDERTALE logo, or websites like redbubble are not
to quote toby himself:
When in doubt, if hand-made and few, it’s OK. If mass-produced and machine/factory made, it’s not OK.