Merch by Amazon operates on somewhat different rules than Etsy-connected POD platforms, and a handful of specific beginner mistakes come up consistently enough that it's worth walking through them directly before you list your first product there.
Trademark and brand name usage gets flagged more aggressively on Amazon than on some other platforms, including phrases that might feel generic but happen to overlap with a registered trademark you're not aware of. Amazon runs automated trademark screening on listing titles and content, and a genuinely innocent phrase can occasionally get flagged if it happens to match an existing trademark — checking the USPTO trademark database for your planned titles and key phrases before listing, especially for anything phrase-based rather than purely visual, is a good habit specific to this platform.
Design file resolution requirements are stricter and more specifically documented on Merch by Amazon than some other platforms — they publish exact pixel dimension requirements per product type, and uploads that don't meet these get auto-rejected rather than flagged for manual review. Checking Amazon's current published specs directly before uploading (rather than assuming your Printful-ready file will automatically meet Amazon's separate requirements) avoids a common early frustration.
Amazon's content policy around what's allowed is also somewhat different in scope from Etsy's — certain categories of content (some forms of political messaging, certain religious content, anything that could be read as promoting violence, even in a clearly satirical or aesthetic context) get reviewed more conservatively, and designs that would sail through on Etsy or a personal Shopify store can get rejected on Amazon specifically. This is worth knowing especially for a gothic or dark-aesthetic catalog, since some imagery in that space (certain occult symbolism, particularly graphic horror themes) sits closer to Amazon's more conservative content lines than it does on other platforms.
Lastly, Merch by Amazon has tiered account levels that start with limited monthly listing slots and expand based on sales performance — new sellers sometimes waste early, limited slots on untested designs rather than starting with their most-proven concepts from another platform. If you're bringing an existing catalog to Amazon from elsewhere, starting with your genuinely best-performing designs, rather than your newest or most experimental ones, makes better use of a limited early tier while you're establishing sales history.