Converting a surface in 3D into a 2D surface

I’m new to slicer. I am looking to create a patch for a hole on a 3d segmentation and then create a 2D representation of that patch which can be measured so I can make a physical patch in real life that will fit. Is something like this even possible or should I explore other 3D editors like Blender?

This is absolutely doable in Slicer.

We’ve actually implemented a Slicer module for 3D planning of fabric patches and looking for students who would be interested in working on the flattening algorithm and doing evaluation on phantoms. Write me a private message (click on my name and then on the email icon) if you are interested.