My better half has been on a new hobby journey lately and wanted me to check out some places to bring home "real" souvenirs. She selected this one, which was near my hotel area. I grew to see how close I was staying to so many interesting places that are off the traditional tourist paths of the city. To enter, ring the bell; signage isn't a huge standout. They'll buzz you in.
The Pressroom and Mercantile is essentially an antique store that focuses on ephemera; as in, things are that were created to be thrown away, not saved. They have all manner of paper goods including soap wrappers, cigar bands, and signage. They also have many traditional antiques and all manner of beautiful old things. Prices are based on quality and scarcity, this isn't the kind of place you can find a hidden bargain in a box, they know what everything is worth.
The store is very clean and impeccably organized. For ephemeral craftists, be sure to look through their damaged boxes for good deals; they price these knowing they'll be cut, torn, and used in artwork. The staff was very welcoming and friendly; they know the history and stories of everything there.
The building itself is worth seeing, it was an old printing shop. The main room has a very high ceiling with bright light. Around the top story are glass windows; this space is used for corporate and private events. If you're looking for a unique place to have a meeting or party, this is it.
Be sure to ask about the book Ephemera, in which they're featured and sell. All in all, it's a great stop for fans of history and anything old.