Using Inkscape and what is cut

I use inkscape for doing all of my projects. I have tried in the past to create pieces that would fit snugly together like puzzle pieces. I loaded the pieces into Easel and then chose the outside path. I cut the pieces and they had a lot of play in them. I recut on the path and they did not fit together. I am wondering if the outside path is cutting on the outside of the stroke width? Or is it cutting outside the mid path the width of the bit?

I guess I just need to know what does the easel program follow, the path of the stroke or the edge of the fill? Does the thickness of the stroke have any effect?

Thanks.

If you choose outside path for each part, things should mate — if you’ve calibrated your machine and determined the endmill’s effective diameter / runout and if you’ve created a suitable gap between the parts.

Start by cutting a right triangle to determine the effective cutting width, then cut a diamond, circle, square test piece.

Once you have the machine tuned and calibrated and know the effective numbers you should be able to cut very tight joints.