Stripe - Any currency. A preferred method with relatively low transaction fees. To cancel, send any email to cancelsubscription@theluddite.org.
LiberaPay - An admittedly-janky not-for-profit Patreon alternative. Only accepts USD. Low transaction fees.
BuyMeACoffee.com - Lower transaction fees than Patreon, but slightly higher than Liberapay and Stripe. Not janky at all.
Or buy a poster! We also sell posters. Choose any illustration on the site.