Be it a note from a family member, an affectionate letter from a lover or simply a friend saying hello, mail often is credited with boosting troop morale during wartime.

Visitors to the National Postal Museum will now be able to read some of the inspirational letters that kept soldiers in good spirits during World War II in “Victory Mail,” an exhibit that opens today.

The display showcases several letters that were sent to and from military personnel from 1941 to 1945 using the V-mail process, in which messages were written on special lightweight paper and then photographed and put onto microfilm. The process was designed to save cargo space for materials vital to the war effort.

“The goal [of the exhibit is to] help illustrate the how mail has moved to and from the armed forces serving around the world,” Assistant Curator Lynn Heidelbaugh wrote in an e-mail. “The power of letters to connect people is often clearly evident in the thoughts and sentiments expressed in the messages, and the depth to which we value communication is also reflected in the measures that the post office and military take to ensure mail delivery in wartime.”

The exhibit took about a year to create and includes letters from several private collections. Posters from the ad campaign promoting the V-mail process also are on display.

Several letters are displayed at the museum in their regular size as well as in the smaller, post-microfilm size.

“You couldn’t send photos and enclosures,” Heidelbaugh said, adding that lipstick kisses on letters used to clog the machines used in the process. “Letter writers do sort of love those little touches, but were not able to do it.”

Prior to being put on the 16 mm microfilm, 150,000 letters would weigh a whopping 1,500 pounds and require 22 mail sacks, according to the exhibit. But once photographed and put on a role of film, the same stack of letters would drop to 45 pounds and would require only one mail sack.

Once the film rolls arrived at their destination, they were blown up to a 4.5-by-5.5-inch letter that was given to the recipient. Soldiers were able to buy magnifying glasses to read the small letters, though they were given the special paper for free.

“[The government] made it as accessible as possible to make sure it spread quickly,” Heidelbaugh said. “This did not replace regular mail, but it did take away the strain of it.”

Between June 15, 1942, and April 1, 1945, some half a billion pieces of victory mail were sent from the United States to military post offices.

V-mail often was shipped by air because planes had a better chance of arriving at their final destination safely. This also made more room for heavier cargo on ships and diversified the means by which mail was sent, lightening the load all around.

While the “Victory Mail” exhibit is considered temporary, it will be open to the public for about two years. The letters that are displayed will be rotated to protect the documents from damage from light.

“Our inspiration was to increase our research and scholarship on the World War II postal operations and letter writing,” Heidelbaugh wrote, “which is one part of the museum’s project to renovate and expand the permanent exhibition on the history of military mail, titled ‘Mail Call.’”