Charging for Design Rendering

I studied Jewelry Design in Europe and now live in the US. A company
asked me to create some designs for them. I usually sketch then do a
gouache rendering. (see example in the attached link).

My question is: How much should I charge for this kind of work? Some
of the rendering take me 10 to 20 minutes to do, some take up to 1
hour. The price I should charge is not only about the time I spent
on making it but also on the design itself.

This company is not making one of a kind piece. the designs I will
give them will be cast and then sold in quantity.

Thank you.
David Kopp

I don’t have a clue as to how much you should charge for your really
nice designs, but it looks to me like you have just given away 61 of
them, to anyone in the world who wants them, for free. :-\ ?

Jerry in Kodiak

Jerry:

Thank you for your concern. These 61 designs are old ones from few
years ago. I think it is like having a web-site with jewelry. people
can have access to it and copy it, this is the same problem. I am not
worried about being copied.

More than 200 people visited the link I posted on my original post.

David Kopp