Mark Twain was a lifelong creator and keeper of scrapbooks. He took them with him everywhere and filled them with souvenirs, pictures, and articles about his books and performances. But in time, he grew tired of the lost glue, rock-hard paste, and the swearing that resulted from the standard scrapbook process. So, he came up with the idea of printing thin strips of glue on the pages to make updates neat and easy to do. In 1872, he patented his "self-pasting" scrapbook, and by 1901, at least 57 different types of his albums were available. It would be his only invention that ever made money.