Is anyone working in a .Net environment using a PDF library to merge PDF files and if so what? I realize this is a DF forum but have inherited a .Net program that does this and have run into a limit of the number of files that can be merged - something like 1200 letters. I don't need to edit the letters in any way, simply to merge them, count pages and be able to search the text in them. And I don't want another command line tool if possible, it's using PDFTK now and that's what hit the limit. I can see the need going up to maybe 2000, possibly more.

TIA