1. Purpose
State whether the model is needed for visualization, a prototype, 3D printing, a structure or further editing.
2. Photographs
Clear views from the front, back, side and at an angle, with as little perspective distortion as possible, are useful.
3. Dimensions
Give the main overall dimensions, and for technical parts the critical dimensions, holes and joints.
4. Movement and assembly
Describe separable elements, hinges, mounting points and the preferred way to assemble the object.
5. Printing
If the desired size, material or printer is known, state it in advance.
6. Format
Say if the file must open in a particular program or meet a workshop's requirements.
7. References
Examples help to define the style and the level of detail.
8. The final check
Before delivery, the scale, the key dimensions, the set of parts and the purpose of the files are confirmed.