Royalties or not for jewellery models?

hello,

I’ve read some topics on here about jewellery but I need to know how you guys do it.

Have you ever included a term such as ‘1% of profit for every cast pieces sold’ ?
With jewellery in particular, models can be printed and cast in big numbers, do I really want a one off $50 (for example) when the person potentially makes thousands out of it ?

I’m also thinking of a passive income, if the person sells the piece designed by me on a regular basis, I think it would be fair I take a little something $.

but even if the terms are set and agreed with by the buyer, what control or knowledge do I have over how many models are cast and sold ? They may lie about it or not even pay. Is this 1% royalty per sold piece realistic AND enforceable?

If it’s all too hard, could I benefit from at least engraving my name into the model, in a discreet area ?

I’m really new to this, please be patient I’m happy to learn and read what you have to say.

Thanks !