I have experience with OpenText Brava Enterprise. I've had the chance to integrate their Viewer in our in-house document management system. This viewer opens up to 100 file formats and allows to add/remove/edit annotations on files and saves these annotations as a separate layer on top of the file. So next time you open the same file to view, you can load the annotations (via API) calls and place the layer of annotations on top.
I was hoping I would see the same thing with Telerik PDF Viewer (and I am aware this works only for PDF). To allow the user to add a Text comment, Shapes, Stamps, Image, PDF Bookmark, etc.
Currently the result of PDFViewer printing is affected by PDFViewer scale option. When scale is less than 200%, the letters in the printed PDF appear blurred.
Text in printed PDF file is blurred
Text in printed PDF file is clear.
NOTE: Clear text may be achieved if PDFViewer scale option is set to 400% on the demo before printing.