Print legibility at distance. The text or character motif should still read clearly from across a convention floor or a classroom. Designs that crowd four lines of small text into a fist-sized chest print usually disappear in event photos and group shots, which is half the point of wearing identity apparel in the first place.
Niche-vocabulary fluency. Strong designs use the language fans use with each other. Words like otaku, weeb, baka, simulcast, and tsundere signal in-group identity the way a stock 'I love anime' wordmark never can, and they earn more recognition nods at meetups and conventions.
Gift-readability without a fan decoder. Gift-buyers who do not watch anime themselves need designs that telegraph the recipient's interest without requiring the buyer to recognize specific shows or characters. Statements like 'just a girl who loves anime' or otaku-pride typography do that work cleanly, and reduce the risk of buying off-canon for the wrong fandom.
Wear-context flexibility. A design should work in at least two contexts: a convention floor or anime-night meetup, plus a casual weekday wear like a coffee shop or a Friday class. Anime t-shirts locked to one ultra-specific scenario limit how often the design makes it back into the rotation.
Trademark-clean composition. Generic-niche designs that do not reference licensed shows, studios, or characters carry less risk of removal from third-party resale platforms and read consistently across changing seasons of the anime calendar.