Can I use photos which are in public domain and out of copyright to print them on souvenirs which I offer as bonuses on kikstarter.com?

To use a photograph without permission from the owner of the copyright, the photograph must either be in the public domain or else your use must be a "fair use." You say that the photographs are in the public domain. As of today, a photograph is absolutely no longer protected under copyright if it was published before 1923. If it was published after that date, you should consult an attorney because the laws regarding term of copyright vary greatly depending on when the photograph was published; if a copyright notice was placed on the photograph; and if the copyright was renewed, among other factors. Even if the photograph is still protected by copyright, a "fair use" is not infringement. Whether your use is commercial or non-commercial is only one factor considered in determining if your use is a "fair use." Other factors include how much of the original photograph you are using and the effect of your use on the value of the photograph. Courts can take into account other factors as well. You mention that the photographs are offered through archives for non-commercial use only - if they are truly public domain, then anyone is free to use them for any reason so I would dig deeper into figuring out if they are truly public domain. Since you are raising money through kickstarter for what will become a commercial enterprise, there is an argument that your give-aways are a commercial use of the photographs. If you have a question, check with the archives in advance - unlike the truism, here it is easier to ask permission than forgiveness in case they don't agree with you. There is one final issue as well. You also need to consider if you have permission to use the likenesses of persons or the images of private buildings or other copyrighted works in the photographs. These people and copyright owners also have rights that need to be considered. I would consult with an attorney to avoid a problem.