Authenticity is the most critical factor when purchasing. Original maps were produced using specific historical methods that leave identifiable markers:
: Genuine antique color was applied by hand. Look for "show-through" on the reverse side of the paper, particularly with greens, which often oxidized and bled through over time. 2. Where to Buy Antique Maps
: These typically leave a plate mark —a subtle indentation just outside the map's border where the metal plate pressed into the paper.
: Maps printed before approximately 1775 often use "laid" paper , made from cotton rags. When held to the light, you should see vertical "chain lines" spaced about an inch apart. Later 19th-century maps use machine-made paper that is more uniform. Printing Impressions :