Hi there. I think you need to full fuse over the fibre paper to get the indentation you want - you don't mention how thick your fibre paper is, I assume you are not making a drop ring out of it, which you would use to slump the glass through.
If you want an indentation you cut out shapes and position those under your fused piece. If you want a relief you cut out the frame of the shape you want and fuse your glass over it.
For both methods you need to make sure your glass is thick enough - at least 2 layers for thin fibre paper, and more for thicker indents/reliefs.
Have a look at this video from Delphi, which shows the various fibre products and how to use them:
https://www.youtube.com/watch?v=8ZcyDRosNSEI am by no means a fusing expert, so those of you who are please arrest me if I have said anything incorrect!