Below is an image of what a V-mail (Victory Mail) looked like. It was a hybrid process used during WWII in America as the primary and secure method to correspond with soldiers stationed abroad.

To reduce the cost of transferring an original letter through the military postal system, a V-mail letter would be censored, copied to film, and printed back to paper upon arrival at its destination.  V-mail correspondence was on small letter sheets (7 by 9 1/8 in.) that would go through mail censors before being photographed and transported as thumbnail-sized images in negative microfilm. Upon arrival to their destination, the negatives would be blown up to 60% of their original size (4 ¼ in. by 5 3/16 in.) and printed.

I know this V-mail is hard to read but if you right click on the image and download it to your desktop you can open it with your desktop picture viewer and zoom in.

This is actually a high-res digital file and will not distort or blur as you zoom in.

On view: V-mail, 1 page only. Page 2 is missing.

Another V-mail. The letter is just one page long.  (If you have trouble reading this click on the image and download it to your desktop.  It is a high-res image and you can then zoom in or enlarge it as you need.)

On view: 1 page