Thanks Ken - that's a great help.
The flashes are not a major issue for now but long term I can imagine them being an issue if I was using for example 100 subfolders.
I ran a test and have attached a screen shot of the output. Not sure why getting two lots of the same output? I think PDF_1.pdf and PDF_2.pdf needed to be in the Folder 1 and Folder 2 and Folder 1PDF_1.pdf and Folder 1PDF_2.pdf needed to actually be inside a new folder. And actually since the desired output is Folder 1PDF_1.pdf and Folder 1PDF_2.pdf inside a new folder, PDF_1.pdf and PDF_2.pdf are not needed as they are the same files asFolder 1PDF_1.pdf andFolder 1PDF_2.pdf
Could you take a look please?