How to sell a design

In the process of getting copyrights on a jewelry line. When this is
accomplished, are companies interested in buying copyrights and
paying “royalties?”. Not sure if these are the correct terms.
Basically, not setup for “mass production”, so want to sell idea and
make $ that way. Anyone familiar with this process and the how to’s,
etc. and what to watch out for.

Thanks, David & Donna

Companies That mass produce do buy designs, but most also will
contract to produce your work at a per unit price, and might even
market them for you paying you a royalty