Get in touch with the New York chapter of the Guild of Bookworkers. They will be able to advise you on where and with whom you can study paper making. Trust me, there is no substitute for thank you notes written on paper you have made yourself which contains your own water mark. It is not as difficult as it may seem. You can also learn to make your own inks, but they will probably not work well in commercial fountain pens...something about the ox gall and the ebonite...but you can attain virtually any color you can imagine. Writing with a steel nib crow-quill pen isn't so very hard to learn and can be quite stunning.
Buzz