This post is on production, pre-production, and prototype molding used in manufacturing, not fungi.
I cannot tell you the number of times companies have contacted the China Lawyers at my firm seeking help in recovering their molds in China (Korea too). But I can tell you the number of times we have felt they had a case worth pursuing: not once. In most instances when a company is seeking to retain an international lawyer to recover molds it has already failed.
If you do not take the right steps with your Chinese Original Equipment Manufacturer (OEM) before you ship over your mold, it is nearly certain you will never get it back. As soon as something goes wrong between you and your Chinese OEM manufacturer, the OEM manufacturer typically will use your mold for ransom. If you tell your Chinese manufacturer that you want your mold back, it will assume that you will be switching to a new manufacturer and it will hold on to your mold, claiming that it does not belong to you.
It is the very rare OEM relationship that lasts forever and if you do not take steps to protect your mold, it will be the even rarer relationship where your Chinese OEM company does not end up with either your mold or your money that you had to pay to get your mold back.
So what are the right steps?
First, get your Chinese OEM manufacturer to agree in a signed writing that the mold belongs to you. Make this clear and do it in Chinese. Second, if possible, get a deposit for your mold, which deposit you will return when the mold is returned to you. Third, and this becomes particularly important if you do not get a deposit (and you almost certainly will not), put in a liquidated damages provision that applies if your mold is not returned when specified.
The right mold agreement with your Chinese OEM manufacturer will not guarantee your mold will return, but the lack of one all but guarantees it will not.