Civil War Engineer Maps on Scratch Paper????

[SwampHunter]

I found a bunch of copies of CW engineer maps and town plat maps and it appears they used scratch paper to make these. Either that or they used black paper and a white Chinese marker.
The paper is black and the markings are white. Anyone know what they used?


Thanks!

[DCMatt]

I've seen scanned images of maps like that at the Library of Congress. Very hard to read... I just assumed they were carbon paper so several copies could be made at once.

I think carbon paper has been around since before the Civil War.

Now that I think about it, if you're looking at used carbon paper, wouldn't the map be backwards?

DCMatt

[findstuf]

they might be Cyanotype.. or "blueprint" it's been around since 1842. Back when it got into surveying, we made copies on a blueprint machine. It stunk like ammonia and "printed" everything with a blue background and white lines. Some older blueprinted documents were on a fabric like "paper".