Printing proxies for Magic: The Gathering (MTG) refers to creating replica cards that are not official or authorized by Wizards of the Coast, the company behind MTG. Proxies are typically used for casual play, testing new deck ideas, or for budget-conscious players who want to use substitute cards.
It's important to note that the production and use of proxies can vary in terms of legality and acceptance within the MTG community. While some playgroups or local events may allow proxies in casual play, most official tournaments and organized play events strictly enforce the use of genuine, authorized card to check the mtg proxy cards