HARRISBURG, Pa. (WHTM) – Once a year, Pennsylvania’s most precious document goes on a journey.

“We have the privilege of bringing out the original charter, the original Penn Charter from 1681, to put on display here at the State Museum of Pennsylvania,” says Aaron McWilliams, Head of Public Service Section at the State Archives.

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For 51 weeks of the year, it stays in the State Archive tower, under special conditions.

“It’s stored in a high-security vault,” says McWilliams. “In that vault we maintain a very steady environment for the document, to preserve it. We try to maintain it at 65 degrees, 35 percent relative humidity, and it is stored in complete darkness.”

But once a year it’s brought out in honor of Charter Day. celebrating the day William Penn received the charter from King Charles II on March 4, 1781.

“The Penn charter of 1681 consists of four pages. Each page measures approximately 23 inches by 31.5 inches. They are parchment, meaning animal skin.” ” Williams explains. “Each page has a border going around, that displays the coats of arms of England, Scotland, and Ireland, and they actually do have France on there, the King was still claiming sovereignty over France. The borders themselves were not drawn in, they’re actually a kind of block printing, stamped in on each of the pages. The writing was all done by hand, hand done throughout the document, very painstakingly done. On the first page, there is an image of an individual, and people assume it’s William Penn. It is not. It’s actually Charles the Second.”

“The actual ink used is iron gall ink, which is a mix of several different ingredients, including gall, which is a kind of a tumor which grows on the bottom of leaves, mixed with iron shavings and water and gum arabic. The ink sits on top of the document, so it’s not absorbed into the document.”

The ink and parchment are two reasons why the Charter is moved so carefully, and kept as close to horizontal as possible. It would be very easy for the ink to chip right off if the parchment is flexed too much.

Though Charter Day is March 4, this year the Charter was brought out on March 10. The Pennsylvania Historical and Museum Commission will celebrate the Commonwealth’s 342nd birthday on March 12 with free admission to many of its historic sites and museums, including the State Museum in Harrisburg. But this might be the last time the charter will be on display there. A new archive building on 6th Street is almost complete.

“It has a home in the new archive already set up,” says McWilliams. “We have a special container to put all the documents in for display and a brand new vault.”

There’s no final decision about bringing the charter back to the museum in the future. But if it’s so delicate, why put it on display at all?

“It’s a connection with history,” says McWilliams. “To see the original document touched by William Penn at the time, so rarely do we get to have such unique and important documents available for people to see. I think it is important people see, yes this is a real document, and see the physical document that an individual touches, that connection to history, that many people look forward to and enjoy.”

For more about PHMC events relating to Charter Day, click here.