One excellent feature of the XSane scanning application is that it can save your scanned documents to Adobe Acrobat PDF format, merely by saving them with a .pdf extension, as in examplefile.pdf . But one not-so-nice feature is the fact that there’s really no expedient way to save multiple scans into a single PDF file. If you do 3 scans, you have 3 PDF files. What now? You need something that can merge (also called “join”) these files into one big beautiful file.
Enter pdftk, or PDF Tool Kit. This is a comprehensive set of tools that can – among other things – merge, split up, encrypt/decrypt, password protect, rotate, and repair PDF files.