Do a prototype to send design proposals to brands?

Hi! , we are a small studio from Barcelona starting with projects of industrial and product design, especially focusing on concepts of lighting and furniture, we are beginning to make proposals to brands and editors but we have a discussion in which we do not get agree.

It is worth making functional prototypes (no cardboard or paper), is a financial investment but we believe to add value to brands and gives them confidence in the proposal.
what you think?

Thnaks so much!!!

Hi Alex,

Unless we had a longstanding relationship with the client, we wouldn’t consider providing a prototype or development work with a proposal, as that should be billable work contained within the scope of the project.

While it may seem impressive to ‘go that extra mile’, in reality I think you might find yourself always needing to go that extra mile to compete at a level you’d be happy with. If you feel like some explanation of your design direction is necessary within the proposal, a vague gestural comp of line drawing sketches would be as far as we would go.

Good luck!