Zazzle.com and cafepress.com both allow you to create a design and print it on multiple shirt styles/sizes. Some students want a polo? Done. Others want a hoodie? Done. Organic t-shirts? Done. Someone wants it on a mug? Done.
This option is a bit more expensive than getting a bulk order, but you can also use these platforms for bulk orders.
Both of these platforms allow you to earn a commission on each sale (if you want to raise money for your club), or set the commission to zero.
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