When burning an image the laser is shadowing the image and not completely filling in the image.
…mmm it’s hard to see…
What I mean is, without seeing what you describe and without knowing/seeing your settings, it is impossible to help seriously.
Perhaps one of the Troubleshooting guides will help:
In particular:
If those don’t help, some good pictures and the lbrn2 file will help us see what you see.