The business of buying and selling ancient coins, vintage sports cards, rare trading cards, classic comic books and old paper money is booming, and one Lakewood Ranch company is at the heart of it.

Certified Collectibles Group includes a number of companies that specialize in evaluating, grading and encapsulating rare items. Their expertise is relied upon by people who deal in collectibles around the globe, and their seal is seen as a guarantee that an item is genuine. In addition to the 290 people who work at Certified Collectibles’ 60,000-square-foot local headquarters, the company has offices in Hong Kong, Shanghai, Munich and London, and has assessed some of the most valuable collectibles in the world, including a Roman coin that recently went for $4.2 million, a world record.

The Certified Collectibles staff walked us through some of their favorite items and how they graded them.

Detective Comics Issue 27

Famous for including the debut of Batman, this 1939 comic was given a 7.0 grade on a scale of one to 10 and sold for $1.5 million. Matt Nelson, the primary grader for Certified Collectibles’ comics division, says when a comic book arrives for grading, his staff looks to make sure the book is complete and examines how yellowed the paper has become. “Whiter is better,” says Nelson. Light, heat, humidity and air are a comic’s worst enemies, he says, and over time they can tan the paper and make it brittle. “Browning really takes away from comics,” says Nelson. “If it’s tanned or dark, it’s a turnoff.”

$100 Bill From 1863

This rare bill, commonly known as a “Spread Eagle,” according to Matt Quinn, the primary grader for Certified Collectibles’ currency business, was among the first paper money produced by the U.S. government. (Before the Civil War, banks issued currency with their names on it as evidence that the money’s value was guaranteed by the bank.) The most common damage to paper money occurs in the most obvious way, when someone folds it to put it in a wallet. This bill, which sold for $432,000, earned a score of 65 out of 70 and the designation “EPQ,” or “exceptional paper quality,” which means the bill has never been recolored or restored in any way. “There are only about 40 of these left on the planet,” says Quinn.

Michael Jordan Rookie Card

Last year, when ESPN began airing The Last Dance, its epic documentary about Michael Jordan’s final season with the Chicago Bulls, interest in basketball cards, and particularly anything to do with Jordan, skyrocketed. That included interest in this Fleer card, which is considered the most popular basketball card ever made. Andy Broome oversees sports card grading for Certified Collectibles. In addition to examining the centering of a card and the condition of the surface, he also looks at how sharp the corners of the cards remain. Even a slight bend can reduce its value. Certified Collectibles only recently began grading sports cards. This is a mockup of what one of its encapsulations will look like.

Black Lotus Card From Magic: The Gathering

The most sought-after card from Magic: The Gathering, the world’s first trading card game, is a rare Black Lotus card from the first Magic printing in 1993. The card’s estimated worth starts at $100,000. Trading cards have a coating that makes them more durable than comics, says Quinn. When looking at a card, he examines how centered the main image is and how well preserved the surface is. Even sliding a card across a table or leaving a fingernail indentation can dramatically lower its value.

Ancient Roman Coin

Created in 42 B.C., this coin was commissioned by Brutus to commemorate the assassination of Julius Caesar, hence the daggers in the design and the inscription “EID MAR,” which in Latin stands for “The Ides of March.” There are only three known coins like this in the world, and the particular coin Certified Collectibles graded recently sold for $4.2 million, a world record for a coin. Certified Collectibles uses advanced technology to examine coins, including an X-ray fluorescence spectrometer, which can determine the actual elements present in a piece, to determine whether a coin is counterfeit. There’s no way of knowing the exact lineage of this coin, but Max Spiegel, the president of Certified Collectibles, hypothesizes that it was kept as a presentation piece by a wealthy family and passed down for thousands of years, which would account for its excellent condition.