Hi Chipp, yes like Danny writes above using Trim is the regular way to embed a curve onto a surface such that it divides the surface into multiple separate pieces.

Trim does have planar curve projection built into it as well, so for many cases you can just trim directly to the 2D curve rather than doing the projection as a separate intermediate step. But if you want to only cut one side of a closed surface like that, you would either do the projection separately and then trim only with one of the results, or you could also extrude the cutting curve into a solid that only went through one side of the target object and then use the extruded piece as the cutting object in Trim.


> 2. How would I only "stencil" it onto the front and not the back (2)? OK, I can
> answer that one --> USE CLOSEST POINT.

The main way for projection is to just delete the back side one that you don't want. The "closest point" method of project will do a different type of projection where it sort of sucks down the curve by dropping it to the closest point it can find on the surface rather than projecting it along a specific single direction. This results in a different kind of shape of the projection and also it tends to be rather finicky if the curve is not pretty close to the surface and can tend to make a poor quality result, the mechanism that does it still needs to be reworked somewhat.

- Michael