I'm trying to create an image of a board (wood, silver, or gold) that is carved with some ornamentation, e.g.
The purpose is to create an imaging that will later be cut with a laser machine. Therefore I first create the image in SVG, using inkscape (laser machine accept only VG), than I import the SVG in to Blender.
In Blender I grab only the ouyline, pull it down and create a Face (i.e. the board) and I use the rest of the part to carve through the board
I tried 2 method of carving through the Board - Knife Project, and Boolean Difference.
The methods works well when working with more simple structures, e.g:

But than other structure gets distorted, like in the images above.
My questions are:
- Is there a better way to do it than the methods above?
- How can I avoid/or clean the distortion in the image?
Edit:
As explained in How can I model Gothic style windows? (credit to ardito comment)
You don't actually need to separate the board and than curved it, instead:
- open the SVG in InkScape and change the image to be filled (instead of only stroke)
- import the SVG to blender
- select the important mash and do ALT C and turn it into a mash
- now you can simply extrude it and create a 3D img with carved spaces.

unfortunately it doesn't work on complicated image, such as this:

import the SVG version of this image cause blender to convert some of the colors: i.e. black becomes transparent and vice versa.
If I tried to use the boolean difference than blender crashes.
the knife project seems to work - it took about 10 minutes to complete, now I need to delete about 100 faces - but this sometime fails to delete the correct face.


