Patent Drawings
If you invent something that you believe to be unique and commercially viable, you should consider applying for a patent to protect your right to its use. In which case, and at some point, Patent drawings will be required.
A patent will give you the right to prevent others from manufacturing, importing, using or selling your invention without your permission for a set period of time in the country or countries in which you hold that patent.
A new component or innovative product - eg a new type of lid for a drinks carton which keeps the contents fresh for longer. An industrial process or way of making or manufacturing something eg a new plastic-moulding technique. New apparatus or equipment used in an industrial process - eg a new kind of tool for cutting metal.
Having professionally produced drawings further strengthens your design and helps to avoid any ambiguity at a later stage.