Secure transaction for buying and selling expensive paintings

[nata_paint]

Good day!

I apologize in advance , if not in the form of sales of Topeka , but I just did not see another suitable topic for my question.

I am the owner of an expensive painting, there is a buyer , there is a mutually satisfactory price.

Please tell me how to safely conduct transactions for buying and selling pictures?
Surely there are some workloads using may deposit boxes or patterns of credit or other instruments that guarantee security for both sides? What to conclude a contract and that it must be taken into account?
Desirable that when these schemes were reflected the request in cash ( no desire to lose 13%).

Thanks in advance for " chew " answers.
If in the wrong section , I apologize, please move where you want )